Autumn/Winter 2011/12 - Harcourt Arboretum - University of Oxford
Autumn/Winter 2011/12 - Harcourt Arboretum - University of Oxford
Autumn/Winter 2011/12 - Harcourt Arboretum - University of Oxford
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<strong>Autumn</strong>/<strong>Winter</strong> <strong>2011</strong>/<strong>12</strong><br />
79<br />
The <strong>University</strong> <strong>of</strong> <strong>Oxford</strong><br />
Botanic<br />
Garden<br />
News<br />
For friends and supporters<br />
<strong>of</strong> the <strong>University</strong> <strong>of</strong> <strong>Oxford</strong><br />
Botanic Garden and<br />
<strong>Harcourt</strong> <strong>Arboretum</strong><br />
Contents | A few words… | Invaluable volunteers | Recent developments<br />
Education update | The Bobarts Group | Visits and events for Friends<br />
Garden and <strong>Arboretum</strong> events | The last word
2 Botanic Garden News | No. 79<br />
A few words...<br />
Timothy Walker is Director <strong>of</strong> the Botanic Garden and<br />
<strong>Harcourt</strong> <strong>Arboretum</strong>; part <strong>of</strong> his job involves lecturing to<br />
undergraduates not only on plant lifecycles but also on<br />
control <strong>of</strong> invasive species.<br />
by<br />
Timothy<br />
Walker<br />
Is biology a science or was Lord Rutherford<br />
correct when he claimed “that which is not<br />
physics is stamp collecting” It seems harsh<br />
on the chemists but the boundary between<br />
physics and chemistry has always struck<br />
me as very fuzzy. The problem with biology<br />
is that it is rarely black and white, and<br />
particularly ecology and plant conservation.<br />
Whilst punting up the River Cherwell at the<br />
beginning <strong>of</strong> August the plants that I thought<br />
were duckweed (Lemna gibba) were actually<br />
a mixed community <strong>of</strong> Lemna and Azolla,<br />
known variously as mosquito fern, fairy fern,<br />
water fern or duckweed fern. Now you might<br />
think that a mat <strong>of</strong> this non-native species is a<br />
Bad Thing. But the truth is complicated.<br />
“Duckweed fern” is a good common name<br />
for use in countries that have duckweed.<br />
Elsewhere in the world Azolla is known as<br />
“Mosquito fern” derived from a belief, perhaps<br />
misplaced, that if the surface <strong>of</strong> a pond is<br />
covered with Azolla then the mozzies cannot<br />
lay their eggs in the water. The weed may<br />
indeed help to reduce the amount <strong>of</strong> oxygen<br />
available to the larvae and so help to control<br />
mosquitoes. A thick mat, however, will shade<br />
out any other plants in the pond and may<br />
result in the death <strong>of</strong> fish and invertebrates.<br />
“Water fern” is a good name because<br />
Azolla is a fern that floats on the surface <strong>of</strong><br />
the water, but it is not the only floating fern.<br />
Another is Salvinia which is closely related<br />
and which has occasionally been placed<br />
in the same family as Azolla. The former,<br />
however, is not hardy at all whereas the latter<br />
will survive the British winter even though it<br />
is originally from tropical to warm temperate<br />
regions <strong>of</strong> America.<br />
The country <strong>of</strong> origin is perhaps irrelevant<br />
as Azolla has now spread throughout the<br />
world. It is not considered to be a true UK<br />
native species having been introduced as<br />
an ornamental in the 1840s. Its habitat is<br />
ponds or larger areas <strong>of</strong> standing water and<br />
it is not very salt tolerant. This summer may<br />
have been the coldest for twenty years but<br />
it has not been very wet and for much <strong>of</strong> it<br />
the Cherwell and its tributaries have been<br />
flowing very slowly. This, coupled with the<br />
absence <strong>of</strong> serious frosts in <strong>2011</strong>, has meant<br />
that the Azolla has been very happy.<br />
Azolla has a deserved reputation as an<br />
invasive thug because it can grow very fast.<br />
It has been shown to double its weight in<br />
three days. Part <strong>of</strong> the reason for this is that<br />
inside its leaves are chambers containing<br />
colonies <strong>of</strong> a cyanobacteria, Anabaena<br />
azollae, which can fix atmospheric nitrogen.<br />
This puts the Azolla at a selective advantage<br />
over its neighbours because its growth is<br />
not limited by the amount <strong>of</strong> nitrogen in the<br />
water. The real limiting factor for this plant<br />
is phosphorous but not in English rivers into<br />
which fertiliser leaches.<br />
The ability <strong>of</strong> Azolla to fix nitrogen has<br />
been recognised and exploited by farmers in<br />
China for over a millennium. Azolla is grown<br />
in rice paddies around the plants and this<br />
helps to suppress the weeds in the fields.<br />
A mixed community <strong>of</strong> Azolla and Lemna<br />
After the crop is harvested and the water has<br />
drained away, the mat <strong>of</strong> nitrogen-rich Azolla<br />
can also be ploughed into the soil before the<br />
next crop.<br />
It has been calculated that Azolla can<br />
provide up to a tonne <strong>of</strong> nitrogen per acre<br />
per year. If you have Azolla growing on a<br />
pond in your garden it can be scooped out<br />
and used as a very good compost accelerator.<br />
Azolla is also thought to be a nutritious<br />
food for stock including chickens. If you<br />
have neither a compost heap nor chickens<br />
you may want to control the plant. A<br />
recently developed option is to exploit a<br />
herbivore that was probably introduced
Botanic Garden News | No. 79<br />
3<br />
into the UK unintentionally with plants<br />
before the 1920s. The tiny 2mm-long weevil<br />
Stenopelmus rufinasus has been here for<br />
decades and yet has found no other plants<br />
palatable. It is therefore now acceptable to<br />
release large numbers <strong>of</strong> the weevil even<br />
on Sites <strong>of</strong> Special Scientific Interest (SSSI).<br />
Using one introduced organism to control<br />
another is a risky business but in this case it<br />
seems to be safe.<br />
Azolla is odd. It is a fern, as already<br />
mentioned, but it does not produce clouds<br />
<strong>of</strong> spores from the underside <strong>of</strong> its leaves, as<br />
do bracken and the like. The floating green<br />
plants <strong>of</strong> Azolla produce a structure found in<br />
very few ferns – a sporocarp. This is a vessel<br />
which contains the sporangia that produce<br />
the spores. (The rusty pustules on the<br />
underside <strong>of</strong> terrestrial ferns are sporangia.)<br />
However Azolla, unlike most ferns, produces<br />
two types <strong>of</strong> sporangia, male and female,<br />
and so two different sporocarps. The female<br />
sporocarps are smaller but they contain<br />
just one sporangium which produces just<br />
one female spore. When conditions are<br />
right, the spore germinates and grows into<br />
the female gametophyte inside the spore<br />
but this then bursts through the spore wall<br />
Azolla on the River Cherwell in <strong>Oxford</strong><br />
revealing several archegonia each with one<br />
egg. (In case it has slipped your mind, the<br />
gametophyte is a stage in the life <strong>of</strong> plants<br />
that has no equivalent in the life <strong>of</strong> animals<br />
and fungi. The gametophyte is responsible<br />
for producing gametes: sperm in antheridia<br />
and eggs in archegonia.)<br />
The male sporocarps are 2mm in<br />
diameter and contain many male sporangia<br />
which each produce many male spores<br />
which, despite being released from the male<br />
sporocarps, hang together in a mass called a<br />
massulae. The spores have a barb (a glochidium)<br />
and this also helps the group <strong>of</strong> spores<br />
hang on to a female spore that contains the<br />
female gametophyte. Inside each male spore<br />
a male gametophyte develops, upon which<br />
develops one antheridium that produces<br />
just eight sperm. These swim to the archegonium<br />
and fertilise the egg. The resulting cell,<br />
the zygote, divides and grows into the green<br />
Azolla plant and the life history is complete.<br />
Despite its current dubious reputation<br />
Azolla has a past that might make it important<br />
in the future. A long, long time ago in<br />
the Eocene, 55.8 to 37.2 million years ago,<br />
the continents were distributed differently<br />
from their current arrangement. In particular<br />
there was an ocean on the North Pole that<br />
was almost completely surrounded by land<br />
and thus cut <strong>of</strong>f from the deep, global ocean<br />
currents. At this time, the Earth was so warm<br />
that the flora near the poles was what we<br />
now consider to be sub-tropical.<br />
The isolation <strong>of</strong> the Arctic Ocean and the<br />
high temperatures led to an odd, layered<br />
arrangement <strong>of</strong> the water in the ocean<br />
similar to that found in the Black Sea today.<br />
This consisted <strong>of</strong> a layer <strong>of</strong> relatively warm<br />
freshwater (from the rivers surrounding<br />
the Ocean) on top <strong>of</strong> colder and denser salt<br />
water. This was particularly so around the<br />
edge where the water was also enriched with<br />
minerals such as phosphorous washed in<br />
by the rivers. These were perfect conditions<br />
for Azolla, which grew like Topsy, taking up<br />
vast amounts <strong>of</strong> carbon dioxide. It has been<br />
calculated that over an 800,000 year period<br />
the Azolla, which covered up to four million<br />
square kilometres, caused an 80% drop in<br />
carbon dioxide levels from 3,500 ppm to<br />
650 ppm.<br />
As the Azolla died and sank in the waters<br />
its decay was halted and the carbon was not<br />
released. It was then even more securely<br />
locked away on the bed <strong>of</strong> the ocean in<br />
sedimentary layers. This huge decline in<br />
carbon dioxide levels started the chain <strong>of</strong><br />
events that led to the present global climate<br />
with ice at the poles rather than palm trees.<br />
Perhaps this could be considered in the<br />
search for a method <strong>of</strong> sequestering and<br />
removing carbon dioxide today We think<br />
Azolla is an invasive thug, but perhaps it<br />
could be our saviour As I said at the beginning,<br />
biology is rarely black and white.<br />
Azolla with sporocarps
4<br />
Botanic Garden News | No. 79<br />
Invaluable volunteers<br />
by Alison Foster,<br />
Mary Isaac and Tom Price<br />
“It was an enjoyable and relaxing<br />
experience, nice people to chat<br />
to and share garden stories with.<br />
Now I’m doing more volunteering.<br />
It’s not like weeding at home, the<br />
surroundings make it worthwhile!”<br />
Isabelle Kandler, weeder<br />
Victorious over the Nothoscordum: volunteers (l-r) Rose Holman, Ruth Sutherland,<br />
Sally Strang and Isabelle Kandler<br />
For several years the clamor from the Friends to get their hands dirty<br />
and volunteer in the Garden and <strong>Arboretum</strong> has been steadily growing.<br />
With the arrival <strong>of</strong> the new Senior Curator Alison Foster and <strong>Arboretum</strong><br />
Curator Ben Jones in spring <strong>2011</strong>, we started thinking about ways the Garden and<br />
<strong>Arboretum</strong> could welcome more volunteers. <strong>2011</strong> is designated the International<br />
Year <strong>of</strong> Volunteers, building on the success <strong>of</strong> the first IYV held in 2001, and<br />
in July PlantNetwork, the national network <strong>of</strong> botanic gardens, arboreta and<br />
other documented plant collections, organised a conference on Volunteers<br />
in Botanic Gardens and Arboreta. The timing was perfect as we at the Garden<br />
and <strong>Arboretum</strong> were keen to learn from others who had experience <strong>of</strong> the<br />
benefits and challenges <strong>of</strong> using volunteers. Alison, Ben and Mary Isaac, Friends’<br />
volunteer co-ordinator, went to the conference, held at the <strong>University</strong> <strong>of</strong> Bath.<br />
We attended sessions on volunteer strategy and policy, employer-supported<br />
volunteering, volunteers and the law, and many other topics. We came away<br />
inspired and determined to make the most <strong>of</strong> the information we had gathered,<br />
and we are now starting to develop a long-awaited volunteer programme.<br />
Volunteer Keith Holmes planted hundreds<br />
<strong>of</strong> trees on Palmer’s Leys at the <strong>Arboretum</strong><br />
Friends have been involved in volunteering<br />
since the beginning <strong>of</strong> the organisation<br />
twenty years ago and have helped in<br />
many ways: running the biennial plant<br />
sale, organising visits to gardens, doing<br />
administration and assisting at special events<br />
and at Friends’ c<strong>of</strong>fee mornings. However,<br />
volunteer members <strong>of</strong> the Friends have,<br />
for many years, been requesting that they<br />
could be more ‘hands on’ at the Garden and<br />
<strong>Arboretum</strong>, and this year we have been given<br />
invaluable help by a series <strong>of</strong> keen volunteers<br />
from the Friends and elsewhere. Several<br />
projects have been on the go since spring<br />
<strong>2011</strong>, all <strong>of</strong> which have proved to be a huge<br />
success, benefiting both the Garden and the<br />
<strong>Arboretum</strong>, and the individuals involved.<br />
The first group <strong>of</strong> volunteers responded<br />
to our cry for help in dealing with<br />
Nothoscordum x borbonicum, a bulbous<br />
plant native to South America and the<br />
Garden’s worst pernicious weed. For<br />
decades Garden staff have struggled to keep<br />
on top <strong>of</strong> this. Various methods <strong>of</strong> control<br />
have been employed, including treatment<br />
with glyphosate, soil removal and even high<br />
voltage electrocution! However, nothing<br />
seems as effective as hand weeding.<br />
The first team <strong>of</strong> volunteers arrived at<br />
the Garden on a beautiful sunny morning in<br />
April <strong>2011</strong>. A meet and greet ensued, so that<br />
we each knew who was who, followed by an<br />
induction to explain the problem at hand<br />
and how we planned to manage it. We spent<br />
the morning weeding the <strong>of</strong>fending plant<br />
out <strong>of</strong> the vegetable beds. The team were<br />
amazed at its tenacity: how could it produce<br />
so many bulbs, be so tiny and such shades<br />
<strong>of</strong> brown as to be camouflaged against the<br />
soil The work required hand weeding and<br />
sifting <strong>of</strong> the soil, slowly working through<br />
each bed.<br />
This may sound neither interesting nor<br />
glamorous, but the volunteers involved<br />
really enjoyed doing it. They loved working<br />
in a team, being in the peace <strong>of</strong> the Botanic<br />
Garden, in beautiful surroundings and also<br />
found the task very satisfying.<br />
The same team returned fortnightly<br />
for three months to weed two beds in the<br />
Monocot quarter, where Nothoscordum was<br />
particularly prevalent. The first team then<br />
passed the baton to a second team who<br />
completed their three-month stint at the<br />
end <strong>of</strong> September.<br />
The impact on the Nothoscordum<br />
population has been huge. The teams<br />
have managed to eradicate completely the<br />
large parent bulbs from the beds and have<br />
significantly reduced the number <strong>of</strong> smaller,<br />
daughter bulbs. This means that there will be<br />
fewer bulbs <strong>of</strong> flowering age next spring, so<br />
less dead heading required to avoid seeding.<br />
“As a way to support the Garden,<br />
I can’t recommend volunteering<br />
highly enough and hope our<br />
experience will encourage other<br />
Friends to become involved in a<br />
hands-on way too.”<br />
Ruth Sutherland, weeder
Botanic Garden News | No. 79<br />
5<br />
Nothoscordum bulbs<br />
If this project continues, we’re confident that<br />
we can bring the Nothoscordum population<br />
down to a manageable level and, hopefully,<br />
eradicate this menace completely in the<br />
longer term!<br />
Meanwhile, other volunteer projects at<br />
the Garden and the <strong>Arboretum</strong> have included<br />
weekly watering <strong>of</strong> newly planted material<br />
during the very dry spring; dead heading;<br />
dividing and potting up plants from the<br />
Herbaceous and <strong>Autumn</strong> Borders ready for<br />
the Friends’ plant sale next summer; planting<br />
bulbs; a volunteer gardener for the vegetable<br />
beds; volunteer involvement in clearing<br />
Rhododendron ponticum at the <strong>Arboretum</strong>;<br />
and data entry on our new plant records<br />
database. The Friends’ Administrator also has<br />
regular and invaluable administrative help<br />
from a volunteer member <strong>of</strong> the Friends.<br />
Without the help <strong>of</strong> these individuals we<br />
could not have maintained the collections to<br />
the level achieved this year, nor continued<br />
developing the Garden and <strong>Arboretum</strong> for<br />
the years ahead. It has been an absolute<br />
“Volunteering at the<br />
Botanic Garden is not<br />
only fun and rewarding<br />
but it gives me the<br />
opportunity to feel<br />
part <strong>of</strong> the team and to<br />
learn from the experts.<br />
It’s also great knowing<br />
you’re doing something<br />
to help and that all the<br />
vegetables that we’ve<br />
so lovingly grown go<br />
to people who really<br />
appreciate them.”<br />
Ness Newman, who has<br />
been volunteering half<br />
a day a week since July.<br />
She works on the vegetable<br />
beds with Jim Penny <strong>of</strong><br />
the Hardy Team.<br />
pleasure to have enthusiastic and committed<br />
volunteers working with us and we<br />
would like to say a very big thank you to all<br />
our volunteers, past and present, for their<br />
hard work and positive influence on the<br />
Garden and <strong>Arboretum</strong>.<br />
We are now developing a bigger<br />
programme for volunteers at both the Garden<br />
and the <strong>Arboretum</strong>. There will be roles in<br />
maintenance <strong>of</strong> all sorts, both regular activities<br />
and one-<strong>of</strong>f projects: planting, dividing,<br />
weeding, dead heading, potting, grass edging,<br />
leaf picking, watering, clearance work, plus<br />
data entry and library administration. And<br />
we still have lots <strong>of</strong> the ‘usual’ activities for<br />
Friends to help with – the Friends’ plant sale,<br />
special events, c<strong>of</strong>fee mornings, garden visits,<br />
festivals and picnic days.<br />
If you or anyone you know would<br />
be interested in joining the volunteers,<br />
please contact us at:<br />
volunteers@obg.ox.ac.uk or by post to:<br />
Volunteers, <strong>Oxford</strong> Botanic Garden,<br />
Rose Lane OX1 4AZ. Thank you.<br />
A volunteer’s<br />
experience<br />
by Sally Strang<br />
When I replied to a request for weeders<br />
at the Botanic Garden I did wonder<br />
whether this was a rather rash decision.<br />
Did I really want to weed another patch<br />
when there was plenty to do in my own<br />
garden Three months seemed a long<br />
time to commit to, albeit for only a couple<br />
<strong>of</strong> hours every two weeks, and it wouldn’t<br />
be much fun if the weather was cold<br />
and wet. As it happened it was a magical<br />
spring - warm, sunny and dry.<br />
On our first morning our small group<br />
<strong>of</strong> volunteers was greeted warmly by<br />
Mary Isaac and Tom Price and after<br />
a short health and safety session we<br />
were introduced to the noxious weed<br />
whose rampage through the Garden<br />
was the reason for our recruitment.<br />
Nothoscordum had defied all attempts at<br />
eradication and it had been decided that,<br />
perhaps as a last resort, teams <strong>of</strong> weeders<br />
working methodically through the beds<br />
might slow down its progress. Tom<br />
explained carefully what was expected<br />
<strong>of</strong> us; he and his staff were always<br />
welcoming and were there to answer our<br />
questions, though at no time did we feel<br />
that someone was hovering over us.<br />
Each week we were shown where<br />
to weed and set to work at our own<br />
pace, chatting or comparing the size<br />
<strong>of</strong> a particularly fecund specimen or<br />
just taking in the tranquility <strong>of</strong> our<br />
surroundings. It was a pleasure watching<br />
the changes in the Garden through<br />
the spring. The birds sang, the bells in<br />
Magdalen Tower reminded us it was<br />
c<strong>of</strong>fee time, inquisitive ducks investigated<br />
and groups <strong>of</strong> school children<br />
chattered past clutching their finds. We<br />
marveled at the blue <strong>of</strong> the irises and the<br />
smell <strong>of</strong> spring enveloped us.<br />
On each return visit we would eagerly<br />
scan the six foot’s worth <strong>of</strong> bed which<br />
we had weeded last time to see if any<br />
Nothoscordum had dared to reappear.<br />
On the whole the beds seemed reasonably<br />
clear and it will be interesting to see<br />
what happens next year.<br />
We all felt quite sad at the end <strong>of</strong> our<br />
term but enjoyed a picnic lunch with the<br />
garden staff and the lovely scones and<br />
jam which they produced for us. Everyone<br />
seemed to think that we had made a<br />
difference and were really grateful and on<br />
our part we felt that it had been a privilege<br />
to work in the Garden. I’m not sure what<br />
my motivations were but it was lovely<br />
to be more involved and to learn in the<br />
process. I would highly recommend it!
6<br />
Botanic Garden News | No. 79<br />
Recent developments at the<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> Botanic Garden<br />
and <strong>Harcourt</strong> <strong>Arboretum</strong><br />
by<br />
Timothy<br />
Walker<br />
It is universally acknowledged that this has been a very good year for fruits.<br />
The possible reasons fall into two groups. Firstly, there was nothing to<br />
upset flowering and thus pollination <strong>of</strong> those flowers. Although December<br />
2010 was bitterly cold, in central <strong>Oxford</strong> we have escaped serious frost so far<br />
in <strong>2011</strong>. The winter flowering plants were late but then spring was a bit early<br />
and spectacular. Secondly, the conditions through the summer may not have<br />
been good if you were camping, but if you were a plant growing and swelling<br />
fruits, they were perfect.<br />
The many and various fruits <strong>of</strong> the family<br />
Rosaceae are especially abundant this year.<br />
The flowers <strong>of</strong> the members <strong>of</strong> the Rosaceae<br />
are very easily recognised because in them<br />
it looks as if the stamens are growing from<br />
the base <strong>of</strong> sepals. In fact the stamens,<br />
sepals, and petals all grow around the edge<br />
<strong>of</strong> a cup-like structure called a hypanthium<br />
but the petals fall <strong>of</strong>f before the other<br />
structures do. The hypanthium is in fact<br />
the fused bases <strong>of</strong> these three whorls<br />
<strong>of</strong> structures. However, the fruits <strong>of</strong> the<br />
members <strong>of</strong> the Rosaceae are very varied,<br />
in part due to the hypanthium and the<br />
receptacle that supports all the floral parts.<br />
The division <strong>of</strong> the species in the<br />
Rosaceae into genera has been controversial<br />
since John Ray (the 17th century English<br />
naturalist) was a lad and probably long<br />
before then. In particular it has been very<br />
difficult to see how the 950 species with<br />
pomes can be grouped. A pome is a fleshy,<br />
indehiscent (not opening at maturity along<br />
lines or pores) fruit, consisting <strong>of</strong> a modified<br />
floral tube surrounding a core, as in apples. 1<br />
The plants with pomes are not just<br />
apples but pears, quince, loquat, hawthorn,<br />
medlar, cotoneaster, sorbus and pyracantha.<br />
To quote a 2007 paper 2 there is “limited<br />
Sorbus<br />
sargentiana<br />
Sorbus domestica<br />
forma pyrifera<br />
Sorbus<br />
aria<br />
Sorbus<br />
latifolia<br />
Sorbus domestica<br />
forma pomifera<br />
Sorbus<br />
torminalis
Botanic Garden News | No. 79<br />
7<br />
Rhododendron bashing at the <strong>Arboretum</strong>: (l-r) Director Timothy Walker, trainee Katie Benallick and horticulturalists Richard East and Jim Penny<br />
resolution <strong>of</strong> a complex evolutionary<br />
history”, or to put it another way, we don’t<br />
know what’s related to what. It is a classic<br />
example <strong>of</strong> Darwin’s lament that “we have<br />
no written pedigrees [so] we have to make<br />
out community <strong>of</strong> descent by resemblances <strong>of</strong><br />
any kind.”<br />
The situation is complicated by the<br />
fact that these species don’t seem to know<br />
where the boundaries lie either, and form<br />
hybrids with species in quite different<br />
genera. 3 So for example at the Botanic<br />
Garden we have a hybrid between hawthorn<br />
and medlar (x Crataemespilus) and another<br />
between rowan and pear (x Sorbopyrus). It<br />
is further complicated by the fact that some<br />
species indulge in apomixis, where seeds<br />
are produced without the need for fertilisation,<br />
resulting in very localised variants. It<br />
appears that this is a group which evolved<br />
very quickly a long time ago, but since then<br />
there has been very slow divergence <strong>of</strong> their<br />
DNA. This divergence is very important for<br />
building classifications based on DNA.<br />
A wise old taxonomist once told me<br />
that “where there is confusion at the macro<br />
level there will be confusion at the molecular<br />
level” and in this case he was right. Confusion<br />
can be seen from the fact that in the<br />
1850 guide to the Botanic Garden, written<br />
by Pr<strong>of</strong>essor Charles Daubeny, the applefruited<br />
form <strong>of</strong> the service tree is referred<br />
to as Pyrus domestica. In the 1914 guide<br />
written by Dr Gunther it is Pyrus sorbus.<br />
The current label says Sorbus domestica<br />
forma pomifera. Unfortunately this now<br />
needs to be changed to Cormus domestica as<br />
there is no evidence to support the grouping<br />
together <strong>of</strong> all <strong>of</strong> the species that were<br />
formerly in the genus Sorbus. 4 Interestingly,<br />
the genus had already been sub-divided<br />
into sub-genera (or sections) along similar<br />
lines. 5 If you want to see the differences for<br />
yourself, the Botanic Garden is a splendid<br />
place to do this. We have Sorbus domestica,<br />
S. torminalis, S. sargentiana, and S. latifolia<br />
inside the Garden and there are S. aria trees<br />
on the High Street outside. Our new orchard<br />
includes apple trees and other culinary<br />
species which are already starting to bear<br />
fruit. We also have Cydonia oblonga, Mespilus<br />
germanica, and many other species at<br />
both the Garden and the <strong>Arboretum</strong> and<br />
they are all doing very well this year. Many<br />
<strong>of</strong> their fruits also make terrific jelly.<br />
Not to be outdone the woody plants at<br />
the <strong>Arboretum</strong> have also fruited well. The<br />
squirrels have had a feast on the acorns<br />
which have formed carpets under their<br />
parent trees.<br />
Rhododendron ponticum is an important<br />
plant at the <strong>Arboretum</strong> but it can get carried<br />
away. This year, as every year, some <strong>of</strong> it<br />
has had to be coppiced and grubbed out to<br />
prevent it from swamping other plants. This<br />
also reduces the risk <strong>of</strong> invasive diseases,<br />
such as Phytopthora, spreading.<br />
Orchard planting at the Botanic Garden
8<br />
Botanic Garden News | No. 79<br />
Recent developments at the <strong>University</strong> <strong>of</strong> <strong>Oxford</strong><br />
Botanic Garden and <strong>Harcourt</strong> <strong>Arboretum</strong><br />
The fruits <strong>of</strong> Magnolia campbellii ssp<br />
mollicomata have given a good show at the<br />
Garden. These rather unpleasant looking<br />
structures are a vivid cerise with erumpent<br />
orange seeds. Each seed is housed in a<br />
separate ovary which is easier to see at this<br />
time <strong>of</strong> year than in the spring when the<br />
plant is in flower. For the first time that I can<br />
remember, the Magnolia x soulangeana has<br />
also set fruit.<br />
Magnolia campbellii ssp mollicomata<br />
Back at the Garden the fruiting <strong>of</strong> the<br />
woody plants has been matched by the<br />
flowering not only on the <strong>Autumn</strong> Border<br />
but also on the big Herbaceous Border. At<br />
the beginning <strong>of</strong> September this was looking<br />
as good as it has all year, perhaps benefiting<br />
from the mild, wet summer. For many visitors<br />
the highlight <strong>of</strong> the <strong>Autumn</strong> Border has been<br />
not the dahlias but the salvias. In particular,<br />
Salvia oxyphora, which is a pink that you<br />
might think was incompatible with any<br />
other colours and yet it looks wonderful with<br />
Canna musifolia and Dahlia ‘Summer Night’.<br />
Two plants have excelled this year at<br />
producing scent in the evening. Whilst this<br />
is an unhelpful comment when the Garden<br />
closes at 5pm these are two plants which<br />
Friends might like to have at home. The first<br />
is Clerodendron trichotomum var. fargesii. We<br />
grow this against a west facing wall and it is<br />
very happy. The ivory coloured flowers are<br />
presumably pollinated by moths. A tender<br />
plant for a conservatory attached to the house<br />
is Murraya paniculata the scent <strong>of</strong> which<br />
is very similar to that <strong>of</strong> the Clerodendron<br />
outside. We grow it in a shady part <strong>of</strong> the<br />
Palm House. Whilst in this area it is worth<br />
mentioning a new flowering record for the<br />
Garden: for many years we have been nurturing<br />
a plant <strong>of</strong> Cubanola domingensis from<br />
the c<strong>of</strong>fee family, the Rubiaceae. The flowers<br />
are extraordinary – tubular and pale yellow,<br />
they hang vertically downwards, and are<br />
more than eight inches long. We do not know<br />
yet what pollinates it but it is an amazing<br />
example <strong>of</strong> the apparent extravagant, almost<br />
wasteful, nature <strong>of</strong> biology.<br />
1 Harris & Harris (2001) Plant Identification<br />
Terminology. Spring Lake Publishing<br />
(a must-have book for a gardener interested<br />
in plant bits).<br />
2 Campbell CS et al (2007) “Phylogeny <strong>of</strong> sub<br />
tribe Pyrinae” Plant Systematics & Evolution,<br />
Vol 266, pp119-145.<br />
3 Robertson et al (1991) “A synopsis <strong>of</strong> genera<br />
in the Maloidae (Rosaceae)” Systematic<br />
Botany, Vol 16, pp376-394.<br />
4 Potter D et al (2007) “Phylogeny and classification<br />
<strong>of</strong> Rosaceae” Plant Systematics &<br />
Evolution, Vol 266, pp5-43.<br />
5 Bean WJ (1980) Trees and shrubs hardy in<br />
the British Isles, Vol 4, pp399-404.<br />
The herbaceous border at the Botanic Garden
Botanic Garden News | No. 79<br />
9<br />
Education update<br />
by Lynn Daley and Sarah Lloyd<br />
We’re delighted to report that the Garden<br />
Primary Education Officer Emma Williams<br />
had a baby girl, Tegan, in September. We<br />
welcome Leah Whitcher who is covering<br />
Emma’s maternity leave. Leah is an<br />
environmental science and geography<br />
graduate who has worked as a marine ranger,<br />
a gardening journalist and a primary school<br />
teacher, specialising in art and outdoor<br />
education.<br />
We had a very busy summer with lots <strong>of</strong><br />
events including, in July, Alice’s Day and a<br />
Forest Picnic Afternoon, both <strong>of</strong> which drew<br />
large crowds to the Garden to take part in a<br />
variety <strong>of</strong> activities.<br />
To celebrate <strong>2011</strong> as the International<br />
Year <strong>of</strong> Forests, we ran a series <strong>of</strong> family<br />
friendly events throughout August, each<br />
addressing a different aspect <strong>of</strong> trees and<br />
forestry. Though occasionally hampered by<br />
the British summer, these afternoons proved<br />
very popular. There was also a series <strong>of</strong> new<br />
trails at the <strong>Arboretum</strong>, which gave visitors<br />
the opportunity to discover different aspects<br />
<strong>of</strong> the site, on and <strong>of</strong>f the more popular<br />
paths. Each week the trails were linked to<br />
the themes <strong>of</strong> the family friendly events – so,<br />
for example when the event was ‘Trees are<br />
Great for Exploring’, the related trail encouraged<br />
visitors to go ‘Around the World in<br />
Eighteen Trees’.<br />
Our ever-popular autumn programmes<br />
for primary schools began in early September<br />
and have, as usual, booked up very<br />
quickly, giving lots <strong>of</strong> children a chance see<br />
autumn colours and to create autumnal<br />
art works at both the Botanic Garden and<br />
<strong>Harcourt</strong> <strong>Arboretum</strong>. Half-term events for<br />
families included making autumn lanterns<br />
at the <strong>Arboretum</strong> and tie-dying at the<br />
Botanic Garden using natural dyes created<br />
from hedgerow plants.<br />
Leah Whitcher<br />
A-level chemistry students from three<br />
<strong>Oxford</strong>shire schools came to the Botanic<br />
Garden and the <strong>University</strong> Department <strong>of</strong><br />
Chemistry for a programme <strong>of</strong> free activities<br />
during the autumn term. They visited<br />
our Chemistry at the Garden exhibition (see<br />
page 13) and then went to the Department <strong>of</strong><br />
Chemistry for a practical workshop in which<br />
they synthesised indigo. (Natural indigo is<br />
derived from the plant Indig<strong>of</strong>era tinctoria<br />
but the dye can also be synthesised in the<br />
laboratory.)<br />
In October we ran the first <strong>of</strong> a series <strong>of</strong><br />
seasonal primary school teacher CPD (continuing<br />
personal development) courses at the<br />
<strong>Arboretum</strong>. The aim is to help teachers to<br />
make the most <strong>of</strong> the outdoors in their teaching.<br />
The <strong>Arboretum</strong> provided the perfect<br />
venue, with a variety <strong>of</strong> habitats and stunning<br />
autumn colour. The winter course will take<br />
place at the Botanic Garden in January and<br />
will provide teachers with ideas and practical<br />
advice as to how to incorporate outdoor activities<br />
at a time <strong>of</strong> year when many school groups<br />
huddle indoors and miss out on lots <strong>of</strong> handson<br />
learning opportunities.<br />
A badger shelter built by children as part <strong>of</strong> the den-building activity<br />
at the ‘Trees for Materials and Shelter’ afternoon at the <strong>Arboretum</strong> in August<br />
A-level chemistry students synthesise indigo
10<br />
Botanic Garden News | No. 79<br />
The Bobarts Group<br />
giving extra support to the Garden and <strong>Arboretum</strong><br />
by<br />
Jennie<br />
Turner<br />
The Bobarts Group, founded in 2004, is the<br />
Patrons’ group <strong>of</strong> the Friends. It gives those who<br />
wish to, the opportunity to contribute extra<br />
financial support to the Garden and <strong>Arboretum</strong><br />
on a regular basis. Bobarts members enjoy all<br />
the benefits <strong>of</strong> being part <strong>of</strong> the Friends, plus<br />
a special programme <strong>of</strong> exclusive small group<br />
visits to private gardens. They are also invited<br />
to an annual reception at which they meet<br />
personally the Director, the Senior Curator<br />
<strong>of</strong> the Garden and the Curator <strong>of</strong> <strong>Harcourt</strong><br />
<strong>Arboretum</strong>.<br />
Members join the Bobarts for a number<br />
<strong>of</strong> reasons: one describes it as the chance<br />
“to support the Garden and <strong>Arboretum</strong> and<br />
especially their education programmes and their<br />
conservation and commitment to plant diversity.<br />
The visits to private gardens in small groups,<br />
accompanied by people with similar interests in<br />
gardens and gardening, are particularly enjoyable.<br />
Such groups do not overwhelm even the<br />
smaller gardens and the owners are particularly<br />
welcoming and hospitable.” Many Bobarts have<br />
forged new friendships through their membership;<br />
others are simply happy to give extra<br />
financial support to the Garden and <strong>Arboretum</strong>.<br />
A brief account <strong>of</strong> the events that Bobarts<br />
members have enjoyed this year will give<br />
readers a flavour <strong>of</strong> the outstanding gardens<br />
we have been able to visit. Every year we are<br />
invited to an <strong>Oxford</strong> <strong>University</strong> department<br />
or college to see treasures <strong>of</strong> botanical art and<br />
herbaria hidden away in many <strong>of</strong> the city’s<br />
ancient buildings. This year we visited the<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> Plant Sciences Department<br />
to see the original paintings and herbaria<br />
presented in the book Planting Paradise, a<br />
recent Bodleian publication whose author,<br />
Dr Stephen Harris, Druce Pr<strong>of</strong>essor <strong>of</strong> <strong>Oxford</strong><br />
<strong>University</strong> Herbaria, showed us the collection.<br />
His willingness to share his knowledge with us<br />
was wonderful.<br />
The 17th century barn, Campden House, Gloucestershire<br />
On a perfect spring day in May we visited<br />
The Old Rectory, Farnborough, an outstanding<br />
four acre garden with magnificent views,<br />
whose owner Mrs Caroline Todhunter showed<br />
us round. The deep parallel herbaceous borders<br />
were full <strong>of</strong> rare and interesting plants. The<br />
newly planted small arboretum with a number<br />
<strong>of</strong> rare Quercus trees and the Cornus kousa and<br />
the Davidia involucrata, both clothed in their<br />
spectacular bracts, were outstanding.<br />
Lord Carrington welcomed us to Bledlow<br />
Manor with its beautiful walled gardens,<br />
the famous Lyde Water Garden with paved<br />
parterres and a wonderful collection <strong>of</strong><br />
contemporary sculptures. He walked around<br />
with us and was full <strong>of</strong> amusing and interesting<br />
stories <strong>of</strong> his time as Foreign Secretary. We<br />
then went for a delicious lunch at Mill Barn,<br />
the nearby home <strong>of</strong> Sir Richard and Lady<br />
Lapthorne, whose private garden was so exciting,<br />
with its individual rooms. They shared<br />
their passion for their garden with us.<br />
Kiftsgate Court is a magnificent four acre<br />
garden with spectacular views largely created<br />
by the grandmother <strong>of</strong> the present owner,<br />
Anne Chamber. The introductory talk to<br />
the garden, and then the walk around the<br />
twists and turns amongst the glorious roses,<br />
unusual plants and shrubs, were a delight.<br />
Later we visited Dean Farm, an ambitious<br />
and very successful garden surrounding a<br />
series <strong>of</strong> converted barns and including a<br />
courtyard garden, a sheltered walled garden<br />
with a distinctly Mediterranean theme,<br />
and woodland walks. We were told that the<br />
owner had to import 650 tonnes <strong>of</strong> topsoil to<br />
convert the very alkaline soil to the one that<br />
supports the present variety <strong>of</strong> plants. The<br />
coolness <strong>of</strong> this midsummer evening sent us<br />
inside for a drink in the owner’s warm kitchen<br />
and more stories about the creation <strong>of</strong> this<br />
very special garden.<br />
Sculpture<br />
at Radcot<br />
House<br />
Home Close is the private 2 acre garden<br />
<strong>of</strong> a Bobarts member designed with terraces,<br />
walls and hedges to divide the garden into<br />
ten distinct areas to reflect a Mediterranean<br />
interest with trees, shrubs and perennials,<br />
planted for all year effect. For once we could<br />
Bledlow Manor, Buckinghamshire<br />
enjoy the wine and delicious canapés outside<br />
in the evening sun before we all drove home<br />
in a deluge, such has been the mixed weather<br />
this summer. Radcot House is another very<br />
special exuberant new 2½ acre garden with<br />
sixteen large colourful beds. Calm areas <strong>of</strong><br />
lawn are bisected by a canal and enclosed<br />
by high beech hedges. The extensive use <strong>of</strong><br />
grasses, unusual perennials and interesting<br />
sculptural surprises was a good talking point<br />
as we moved around the garden. We went<br />
on to Campden House with its 1½ mile drive,<br />
set in fine parkland in a hidden valley with<br />
lakes and ponds. The wide walled terrace<br />
in front <strong>of</strong> the house, which was built in<br />
the 17th century and enlarged in the 19th,<br />
leads to a mixed border <strong>of</strong> interesting plants.<br />
The displays in the many pots were one <strong>of</strong><br />
the most original aspects <strong>of</strong> the garden. We<br />
were very privileged to have our tea in the<br />
panelled dining room.<br />
Finally, the Bobarts Day this year was held<br />
at <strong>Harcourt</strong> <strong>Arboretum</strong>. The reception was<br />
followed by a tour with the Director Timothy<br />
Walker and Senior Curator Alison Foster, and<br />
even those <strong>of</strong> us who had visited many times<br />
learnt more about the trees and meadows<br />
than ever before.<br />
Membership <strong>of</strong> the Bobarts costs £140<br />
per annum for individuals and £225 for two<br />
people living at the same address. If you are<br />
interested in joining the group, please contact<br />
the Friends’ Administrator, Liz Woolley, on<br />
secretary@fobg.org, 01865 286690.
Botanic Garden News | No. 79<br />
11<br />
Visits and events for<br />
Friends and their guests<br />
by Jane Annett, Harriet Bretherton and Pauline Coombes<br />
Please book using the accompanying<br />
booking form. Visits tend to get booked up<br />
fairly quickly so to avoid disappointment<br />
please send in your form as soon as<br />
possible. If you have any queries, contact<br />
the Friends’ Administrator, Liz Woolley,<br />
secretary@fobg.org, 01865 286690.<br />
Friends’ c<strong>of</strong>fee mornings<br />
Fridays 2nd December, 3rd February,<br />
2nd March<br />
10.30am on the first Friday <strong>of</strong> every<br />
month (except January and August) in<br />
the Garden’s Conservatory. After c<strong>of</strong>fee a<br />
member <strong>of</strong> staff leads a tour <strong>of</strong> the Garden.<br />
≠≠<br />
No fee and no booking required,<br />
just turn up<br />
Sunday plant tours at the<br />
Botanic Garden<br />
Sundays 13th November, 22nd January<br />
and 25th March, 10.00am until 11.30am<br />
These tours are with the Director Timothy<br />
Walker and are structured around plants<br />
<strong>of</strong> particular interest for the time <strong>of</strong> year.<br />
They are crammed with botanical<br />
information and horticultural tips and<br />
are great fun. A plant list is provided.<br />
≠≠<br />
Friends £2, guests £6<br />
(includes entry to the Garden)<br />
≠≠<br />
No booking required, just turn up<br />
Garden visits<br />
We have had another successful summer<br />
and autumn <strong>of</strong> wonderful trips to very<br />
special gardens. Thank you for your<br />
continued support, we do hope you have<br />
enjoyed the visits and we always welcome<br />
feedback and suggestions for future events.<br />
Next spring Friends are invited to the<br />
following gardens:<br />
Worcester College, <strong>Oxford</strong><br />
Friday 10th February 20<strong>12</strong>, 2.00pm<br />
Worcester College, Walton Street,<br />
<strong>Oxford</strong> OX1 2HB<br />
Colesbourne Gardens<br />
Friday 19th February 20<strong>12</strong>, 11.00am<br />
Colesbourne Park, Nr Cheltenham,<br />
Glos GL53 9NP<br />
By kind permission <strong>of</strong> Sir Henry and Lady Elwes<br />
The tour will take the group through the<br />
gardens to see both the massed display<br />
<strong>of</strong> snowdrops in the wild garden and the<br />
collection <strong>of</strong> rarer cultivars in more formal<br />
surroundings. There are also masses <strong>of</strong><br />
Cyclamen coum, Eranthis hyemalis, and <strong>of</strong><br />
other plants <strong>of</strong> winter interest. There will<br />
be an introductory talk on the history <strong>of</strong><br />
Colesbourne and the Elwes family and the<br />
background to the diversity <strong>of</strong> snowdrops.<br />
C<strong>of</strong>fee will be served.<br />
≠≠<br />
Tickets £15, guests £20<br />
≠≠<br />
Maximum 50 people<br />
Stone House Garden<br />
Saturday 25th February 20<strong>12</strong>, 2.00pm<br />
Wyck Rissington, Cheltenham,<br />
Glos GL54 2PN<br />
By kind permission <strong>of</strong> Mr & Mrs Andrew Lukas<br />
This garden, created over the last twenty<br />
years, is one for all seasons, with an<br />
emphasis on strong structure and good<br />
foliage. There is a bulb flowering every<br />
month <strong>of</strong> the year, even in a frost pocket<br />
on heavy clay. Specialist hellebores appear<br />
in December and the meadow starts with<br />
crocus in early January; by April it is awash<br />
with fritillaries. Tea will be served.<br />
≠≠<br />
Tickets £10 , guests £15<br />
≠≠<br />
Maximum 50 people<br />
Tours <strong>of</strong> the 20<strong>12</strong> Olympic<br />
Games sites in London<br />
Saturday 17th March and<br />
Friday 23rd March 20<strong>12</strong><br />
Coach departing from<br />
Water Eaton Park & Ride, <strong>Oxford</strong>,<br />
at 8.00am, back at c. 7.00pm<br />
Tours led by Blue Badge Guide Mr Ian Gibson<br />
This is a departure from our normal garden<br />
visits, but we thought that it would be a<br />
good way for us to see the Olympic sites<br />
and to hear what has been achieved in<br />
preparation for this historic event. The<br />
tours will start at the Tower <strong>of</strong> London<br />
after a c<strong>of</strong>fee. We will go to Docklands,<br />
Canary Wharf and the Thames Barrier. We<br />
will have lunch/picnic at Greenwich Park<br />
and then see a number <strong>of</strong> venues including<br />
the Olympic park velodrome. There will<br />
be an afternoon stop for tea at the Olympic<br />
village. Our guide is very entertaining and<br />
knowledgeable and will show us some <strong>of</strong><br />
the new landscaping and gardens. Some<br />
walking involved.<br />
≠≠<br />
≠≠<br />
Tickets £30, guests £35 (includes<br />
coach fare but not refreshments)<br />
Maximum 50 people each trip<br />
As part <strong>of</strong> the Garden’s Public Education<br />
Programme there will be a lecture by Pr<strong>of</strong><br />
James Hitchmough on the development<br />
<strong>of</strong> the wildflower meadows at the Olympic<br />
Park, on 22nd March at the Said Business<br />
School in <strong>Oxford</strong> (see page 14). To book visit:<br />
www.oxforduniversitystores.co.uk or use<br />
the form at the back <strong>of</strong> the Public Education<br />
Programme leaflet.<br />
By kind permission <strong>of</strong> The Garden Master<br />
The garden is known for its summer<br />
displays, but the winter is an excellent<br />
time to see its structure as well as<br />
picturesque views and magnificent trees<br />
and shrubs. The College has a collection <strong>of</strong><br />
snowdrops and early bulbs which should<br />
be in flower at the time <strong>of</strong> the tour. We<br />
will be shown around by a member <strong>of</strong><br />
the gardening team who will talk about<br />
the history <strong>of</strong> the garden, the gardening<br />
techniques used, and plans for the future.<br />
Tea will be served.<br />
≠≠<br />
Tickets £10, guests £15<br />
≠≠<br />
Maximum 40 people
<strong>12</strong><br />
Botanic Garden News | No. 79<br />
Double visit to Iford Manor,<br />
Lower Westwood, Bradfordon-Avon<br />
and Derry Nursery<br />
<strong>of</strong> Special Plants<br />
Saturday 14th April 20<strong>12</strong><br />
Coach departing 9.00am from Redbridge<br />
Park & Ride, <strong>Oxford</strong>; back at c. 4.30pm<br />
Iford Manor by kind permission <strong>of</strong><br />
Mrs Elizabeth Cartwright Hignett<br />
This Grade I Italianate garden was designed<br />
between 1899 and the 1930s by the architect<br />
and landscape gardener Harold Peto. It is a<br />
unique romantic hillside garden characterised<br />
by steps, terraces, sculptures, cloisters and<br />
magnificent rural views. The current owners<br />
have restored the layout and planting to<br />
Peto’s original designs. C<strong>of</strong>fee will be served<br />
on arrival. Picnic or pub lunch in Bradfordon-Avon.<br />
In the afternoon we will visit Derry<br />
Nursery <strong>of</strong> Special Plants to have a tour, buy<br />
from the wide selection <strong>of</strong> unusual plants,<br />
and have tea.<br />
≠ Tickets £30, guests £35<br />
(includes coach fare)<br />
≠ Maximum 50 people<br />
The <strong>University</strong> <strong>of</strong> <strong>Oxford</strong><br />
<strong>Harcourt</strong> <strong>Arboretum</strong><br />
Sunday 22nd April 20<strong>12</strong>, 2.30pm<br />
Nuneham Courtenay, Oxon OX44 9PX<br />
By kind permission <strong>of</strong> Mr Ben Jones, Curator<br />
A chance to see the magnificent bluebells<br />
and to meet Ben and hear about plans for the<br />
<strong>Arboretum</strong>. The tour will be followed by tea.<br />
≠ Tickets £8, guests £10<br />
Ros Diamond<br />
Friends’ seed<br />
collection<br />
We will have a limited number <strong>of</strong><br />
packets <strong>of</strong> seeds to give away in early<br />
January. Each packet will contain a<br />
mixture <strong>of</strong> annuals, biennials and<br />
hardy perennials, collected from the<br />
Botanic Garden. To receive your free<br />
seeds, please send an SAE (at least<br />
postcard-sized, and as soon as you<br />
like) to: Friends’ Seed Collection,<br />
<strong>Oxford</strong> Botanic Garden, Rose Lane,<br />
<strong>Oxford</strong> OX1 4AZ.<br />
Rousham House<br />
and Garden<br />
Thursday 3rd May, 2.00pm<br />
Rousham House, near Steeple Aston,<br />
Oxon OX25 4QU<br />
By kind permission <strong>of</strong> Mr & Mrs Charles<br />
Cottrell-Dormer<br />
This is a great opportunity to visit this<br />
wonderful house at Rousham and to<br />
have a guided tour <strong>of</strong> the garden with<br />
the landscape archaeologist James Bond,<br />
whose interest is in the development <strong>of</strong><br />
the English landscape garden. The house<br />
was built in 1635 and has remained in<br />
the ownership <strong>of</strong> the same family ever<br />
since. It was extended by William Kent<br />
in the 1740s, who also designed the<br />
garden. It is one <strong>of</strong> the finest examples<br />
<strong>of</strong> the first stage <strong>of</strong> the evolution <strong>of</strong> the<br />
English landscape garden and is the<br />
best-preserved survivor <strong>of</strong> a William<br />
Kent design. We will have a picnic tea<br />
under the Seven Arches in the garden.<br />
≠ Tickets £16, guests £21<br />
≠ Maximum 40 people<br />
Summer dates<br />
for your diary<br />
The Friends’ plant sale<br />
Sunday 3rd June 20<strong>12</strong><br />
<strong>Harcourt</strong> <strong>Arboretum</strong>, Nuneham<br />
Courtenay, Oxon OX44 9PX<br />
Our planning for the 20<strong>12</strong> plant sale is<br />
well under way and with the completion<br />
<strong>of</strong> the new car park at the <strong>Arboretum</strong> we<br />
hope it will be another great success.<br />
We will be selling an enormous range<br />
and variety <strong>of</strong> plant stock from the very<br />
rare to the more common, including trees,<br />
perennials, annuals, exotics, grasses,<br />
shrubs and kitchen garden plants. We will<br />
also have a useful stall selling secondhand<br />
gardening and cookery books, an<br />
advice table, a great garden-themed raffle,<br />
fabulous refreshments with homemade<br />
cakes, jams and goodies and lots <strong>of</strong> parking.<br />
Admission is free and you will be able to<br />
explore the <strong>Arboretum</strong> and see the glorious<br />
late spring displays <strong>of</strong> trees and flowers,<br />
before or after buying plants (which can be<br />
delivered by wheel-barrow to your car).<br />
All the plants for the sale come from the<br />
Botanic Garden, college gardens, private<br />
collections and members <strong>of</strong> the Friends.<br />
If you are dividing plants this autumn<br />
please remember us and add a few extra<br />
to be sold in June in support <strong>of</strong> the work<br />
<strong>of</strong> the Garden and <strong>Arboretum</strong>. For this<br />
sale we hope to increase our range <strong>of</strong> vegetables,<br />
fruit and herbs, so we will particularly<br />
welcome any donations <strong>of</strong> excess stock<br />
which you may have. To make this event<br />
a success we need many, many plant<br />
donations so if you would like to help please<br />
do contact me at any time. Thank you.<br />
Maura Allen - 01865 311711,<br />
0777 2<strong>12</strong> 7029 or mea@armitstead.com<br />
New College Opera<br />
Wednesday 11th July 20<strong>12</strong><br />
Following the success <strong>of</strong> Salieri’s Falstaff<br />
in <strong>2011</strong>, we are delighted to announce that<br />
New Chamber Opera will be performing<br />
Mozart’s Il Re Pastore in July 20<strong>12</strong>. Attendees<br />
described <strong>2011</strong>’s event as: “a truly excellent<br />
evening” and “a magical evening”. Further<br />
details and ticket prices for 20<strong>12</strong> will appear<br />
in the next newsletter in early March.
Botanic Garden News | No. 79<br />
13<br />
Garden and<br />
<strong>Arboretum</strong> events<br />
The Public Education<br />
Programme<br />
The Garden and <strong>Arboretum</strong>’s <strong>2011</strong>/<strong>12</strong> Public<br />
Education Programme is now well under<br />
way. Tickets are still available for many<br />
events, including the following lectures<br />
and courses:<br />
Undergraduates from the Department <strong>of</strong> Chemistry who helped to design<br />
the Chemistry at the Garden exhibition<br />
Chemistry at the Garden<br />
Open daily during normal Garden opening<br />
hours; continues until early January 20<strong>12</strong>.<br />
The Botanic Garden is hosting a special<br />
exhibition to celebrate <strong>2011</strong> as the<br />
International Year <strong>of</strong> Chemistry. Research<br />
scientists at the <strong>University</strong> <strong>of</strong> <strong>Oxford</strong><br />
Department <strong>of</strong> Chemistry have designed<br />
posters and self-guided activities to<br />
encourage an interest in plant-based<br />
chemistry, to increase the appreciation <strong>of</strong><br />
chemistry in meeting world needs, and to<br />
generate enthusiasm for the creative future<br />
<strong>of</strong> chemistry.<br />
≠≠<br />
No charge other than for Garden entry<br />
A change <strong>of</strong><br />
name...<br />
At the Friends’ AGM in October it was<br />
agreed to update the Friends’ <strong>of</strong>ficial<br />
name from ‘The Friends <strong>of</strong> <strong>Oxford</strong><br />
Botanic Garden’ to ‘The Friends <strong>of</strong><br />
<strong>Oxford</strong> Botanic Garden and <strong>Harcourt</strong><br />
<strong>Arboretum</strong>’. The Friends have supported<br />
the <strong>Arboretum</strong> for many years and we<br />
feel that it is appropriate to reflect this<br />
in our name. The change also supports<br />
the growing emphasis that Garden<br />
and <strong>Arboretum</strong> staff place on working<br />
collaboratively across the two sites.<br />
Family friendly events<br />
at the Garden<br />
Our naturally-decorated Christmas tree,<br />
a firm favourite with children and adults<br />
alike, will be on display in the Conservatory<br />
from late November.<br />
Big Botanic Christmas Tree<br />
Saturday 3rd December, 10.30am-<strong>12</strong>.30pm<br />
Make natural decorations from seeds, leaves<br />
and pods. Take some home and leave some<br />
hanging on our tree.<br />
≠≠<br />
No need to book, just drop in; no<br />
charge other than for Garden entry<br />
Fairtrade Fortnight<br />
Monday 27th February – Sunday 11th March<br />
20<strong>12</strong>, during normal opening hours<br />
Explore the tropical glasshouses, looking for<br />
plants that are grown around the world as<br />
Fairtrade crops.<br />
≠≠<br />
No need to book, just drop in; no<br />
charge other than for Garden entry<br />
International year<br />
<strong>of</strong> forests lecture<br />
Tony Kirkham<br />
Trees – A cut above the rest<br />
Thursday 24th November, 8.00pm<br />
The talk covers various subjects relating to<br />
the growing <strong>of</strong> trees in cultivation. It will<br />
remind the audience <strong>of</strong> where trees come<br />
from, the threats that they face today both<br />
in their natural habitats and in cultivation<br />
and how we must use this knowledge to<br />
help us understand cultivation techniques<br />
such as planting and pruning and keeping<br />
trees stress free.<br />
≠≠<br />
Said Business School, <strong>Oxford</strong><br />
≠≠<br />
Tickets £<strong>12</strong><br />
We apologise for the fact that some<br />
Friends may not have received<br />
the Public Education Programme<br />
leaflet. You can view the leaflet’s<br />
contents on -line at: www.botanicgarden.ox.ac.uk/Education/obgeducation-public-1.html<br />
or, if you<br />
would like to be sent a paper copy,<br />
please contact: secretary@fobg.org,<br />
01865 286690.
14<br />
<strong>Winter</strong> lecture series:<br />
Gardens around<br />
the world<br />
With the Olympics in mind,this special series<br />
<strong>of</strong> lectures brings together leading gardeners<br />
and garden designers to give us their<br />
perspectives on gardening around the world.<br />
≠≠<br />
≠≠<br />
Botanic Garden News | No. 79<br />
Lectures take place at 8.00pm<br />
in the Nelson Mandela Auditorium<br />
at the Said Business School in <strong>Oxford</strong><br />
Tickets cost £<strong>12</strong> per lecture (includes<br />
a glass <strong>of</strong> wine) or £54 for the series<br />
<strong>of</strong> 5 lectures<br />
Dan Pearson<br />
A garden for a thousand years<br />
Thursday 26th January 20<strong>12</strong><br />
The 240 hectare Tokachi Millennium<br />
Forest on Hokkaido, the northernmost<br />
island <strong>of</strong> Japan, is the brainchild <strong>of</strong> the<br />
media entrepreneur Mitsushige Hayashi,<br />
who acquired the land with a view to<br />
<strong>of</strong>fsetting the carbon footprint <strong>of</strong> his national<br />
newspaper business, Tokachi Mainichi.<br />
In this talk Dan Pearson will describe the<br />
genesis <strong>of</strong> the Millennium Forest project,<br />
his involvement in the creation <strong>of</strong> the<br />
masterplan, and the challenges faced in<br />
creating large scale massed perennial<br />
plantings and a monumental sculptural<br />
landform environment.<br />
James Wong<br />
The gardens <strong>of</strong> Singapore<br />
Thursday 9th February 20<strong>12</strong><br />
A unique, contemporary blend <strong>of</strong> East and<br />
West, the tiny ‘Garden City’ <strong>of</strong> Singapore is<br />
fast becoming a global centre for innovation<br />
in tropical horticulture and landscape<br />
design. James Wong will guide us through<br />
the city state’s distinctive emerging garden<br />
design style, from its origins as a vital<br />
outpost for the introduction <strong>of</strong> new plants<br />
across the British empire, to its new multibillion<br />
dollar ‘space age’ botanic gardens by<br />
the Bay.<br />
Elizabeth Banks<br />
Gardening is happiness –<br />
window boxes to the<br />
President <strong>of</strong> the RHS<br />
Thursday 23rd February 20<strong>12</strong><br />
Join us to hear how a passion for plants<br />
led Elizabeth Banks from her own garden<br />
to her current role as President <strong>of</strong> the<br />
UK’s leading gardening charity, the Royal<br />
Horticultural Society.<br />
Isabelle van Groeningen<br />
The Royal Garden Academy<br />
in Berlin: The revival <strong>of</strong><br />
German horticulture<br />
Thursday 8th March 20<strong>12</strong><br />
In 2008 Gabriella Pape and Isabelle Van<br />
Groeningen re-opened the former Royal<br />
Gardeners Training Institute in Berlin.<br />
Europe’s oldest surviving horticultural<br />
training establishment has a new lease<br />
<strong>of</strong> life, and is the foundation for a new<br />
German Horticultural Society.<br />
Pr<strong>of</strong> James Hitchmough<br />
Meadows at the Olympic park:<br />
elysium in the east end<br />
Thursday 22nd March 20<strong>12</strong><br />
The London Olympic Park includes very<br />
large-scale native wildflower meadows,<br />
rather more cosmopolitan creations <strong>of</strong><br />
South African Drakensberg grasslands and a<br />
North American prairie, in gardens that wrap<br />
around the Olympic Stadium. Join James<br />
Hitchmough to hear how and why these areas<br />
were conceived and designed, the process by<br />
which they were established on the ground,<br />
and the role <strong>of</strong> his research over the past 15<br />
years in minimising the risk <strong>of</strong> failure.<br />
Practical horticulture<br />
study mornings at the<br />
Botanic Garden<br />
≠≠<br />
≠≠<br />
≠≠<br />
Led by members <strong>of</strong> the<br />
horticultural team<br />
Study mornings take place between<br />
10.30am and 1.00pm except Successful<br />
staking which begins at 11.00am and<br />
finishes at <strong>12</strong>.30pm<br />
Tickets cost £20 per session<br />
Successful staking<br />
Tuesday 6th March or<br />
Wednesday 7th March 20<strong>12</strong><br />
Learn the skills <strong>of</strong> staking with the horticultural<br />
staff as they stake the herbaceous plants at the<br />
Garden using natural materials harvested from<br />
the <strong>Arboretum</strong> coppice.<br />
Plant propagation<br />
Tuesday 13th March 20<strong>12</strong><br />
This session will include the hows,<br />
whys and wheres <strong>of</strong> propagation, what<br />
equipment to choose and use, appropriate<br />
selection <strong>of</strong> materials, techniques, practical<br />
demonstrations and aftercare.<br />
Citrus care<br />
Tuesday 20th March 20<strong>12</strong><br />
Come along to learn how to cultivate and care<br />
for citrus plants. Topics covered in this session<br />
include the selection <strong>of</strong> species and cultivars,<br />
year-round requirements, potting, feeding,<br />
pruning, pests and diseases <strong>of</strong> citrus.<br />
Cacti and succulents<br />
Tuesday 27th March 20<strong>12</strong><br />
You don’t have to have a vast glasshouse to<br />
grow cacti and succulents successfully. Come<br />
along to find out which species are good for<br />
indoor cultivation, what their year-round<br />
requirements are, how to repot them, what<br />
and when to feed them and what pests and<br />
diseases may affect your plants.
Botanic Garden News | No. 79<br />
15<br />
Botanical illustration<br />
courses at the<br />
Botanic Garden<br />
Rosemary Wise, who has been the Botanical<br />
Illustrator for the <strong>University</strong> <strong>of</strong> <strong>Oxford</strong> since<br />
1965, will lead these courses. Come along to<br />
benefit from her expertise and experience<br />
in the beautiful surroundings <strong>of</strong> the Botanic<br />
Garden.<br />
≠ 10.00am to 4.00pm<br />
≠ Tickets cost £60<br />
(includes a sandwich lunch)<br />
Botanical illustration<br />
for beginners<br />
Saturday 17th March 20<strong>12</strong><br />
Botanical illustration -<br />
intermediate and advanced<br />
Saturday 21st January 20<strong>12</strong><br />
Botanical course at<br />
<strong>Harcourt</strong> <strong>Arboretum</strong><br />
Meadow plants<br />
identification day<br />
Tuesday 29th May 20<strong>12</strong><br />
Led by the Director, Timothy Walker, this<br />
day-long course will teach you basic plant<br />
identification skills and give you the chance<br />
to try these out on the meadow flora in the<br />
beautiful setting <strong>of</strong> <strong>Harcourt</strong> <strong>Arboretum</strong>.<br />
≠ 10.00am to 4.00pm<br />
≠ Tickets cost £60<br />
(includes a sandwich lunch)<br />
Practical course at<br />
<strong>Harcourt</strong> <strong>Arboretum</strong><br />
Creating a wild flower<br />
meadow<br />
Wednesday 6th June 20<strong>12</strong><br />
Join Charles Flowers for this course<br />
looking at the process <strong>of</strong> establishing<br />
a wildflower meadow. The day will<br />
include an illustrated talk and an<br />
outdoor session looking at Palmer’s<br />
Leys, our newly restored meadow.<br />
Topics covered will include buying or<br />
collecting seed, propagating, the effect<br />
<strong>of</strong> soil type and pH, seedbed preparation,<br />
sowing and managing.<br />
≠ 10.00am to 4.00pm<br />
≠ Tickets are £60<br />
(includes a sandwich lunch)<br />
Please book on-line at www.oxforduniversitystores.co.uk, or by completing the booking form in the printed Public<br />
Education Programme leaflet. If you would like us to send you a leaflet, please contact secretary@fobg.org, 01865 286690.<br />
Introduce a new<br />
member to the<br />
Friends and earn<br />
yourself a thank you!<br />
Introduce a family member, friend<br />
or colleague to the Friends <strong>of</strong> <strong>Oxford</strong><br />
Botanic Garden and <strong>Harcourt</strong><br />
<strong>Arboretum</strong> and we will send you a<br />
£5 voucher for each new member<br />
you introduce, to be redeemed<br />
against tickets for Friends’ events<br />
and visits or the Garden’s Public<br />
Education Programme.<br />
There’s no maximum number –<br />
for every new member you introduce,<br />
we will send you a £5 voucher.<br />
Enter your name and membership<br />
number in this form, cut it out and<br />
give it to the new Friend to complete<br />
and return to us; then we’ll send you<br />
your voucher. Vouchers must be<br />
redeemed within <strong>12</strong> months <strong>of</strong> the<br />
date <strong>of</strong> issue.<br />
When complete, please<br />
send this form to:<br />
The Secretary, Friends <strong>of</strong><br />
<strong>Oxford</strong> Botanic Garden,<br />
Rose Lane, <strong>Oxford</strong> OX1 4AZ,<br />
secretary@fobg.org,<br />
01865 286690.<br />
Your details (the Friend introducing a new Friend)<br />
Name<br />
Membership category<br />
Annual single membership @ £28 p.a.<br />
Single life membership @ £560<br />
Bobarts Group single membership @ £140 p.a.<br />
1 Joint membership is open to two people living at the same address<br />
Membership number (on your membership card)<br />
Details <strong>of</strong> the new Friend(s)<br />
I wish to become a member <strong>of</strong> the Friends <strong>of</strong> <strong>Oxford</strong> Botanic Garden in the category indicated.<br />
Title Given name Surname<br />
Title & name <strong>of</strong> second member (if any)<br />
Address<br />
Post town<br />
Email address<br />
Telephone<br />
(please tick) I can be contacted by email about membership, ticket or other queries.<br />
Postcode<br />
(please tick) I would like to receive copies <strong>of</strong> Botanic Garden News by email (three times a year).<br />
(please tick) I would like to receive occasional extra news updates by email.<br />
Payment <strong>of</strong> annual membership fees<br />
It is very helpful to the Friends if annual membership fees are paid by Direct Debit.<br />
You will receive an initial 15 months’ membership for the price <strong>of</strong> <strong>12</strong> if you pay by Direct Debit.<br />
Please send me a Direct Debit mandate; or<br />
I enclose a cheque for £ ________ (payable to The Friends <strong>of</strong> <strong>Oxford</strong> Botanic Garden)<br />
Gift Aid<br />
Please sign and date below if you are a UK tax payer. This will allow the Friends<br />
to recover tax amounting to 25% <strong>of</strong> your subscription at absolutely no cost to yourself.<br />
I wish the Friends <strong>of</strong> <strong>Oxford</strong> Botanic Garden to reclaim tax on all subscriptions and donations I have made to<br />
the organisation in the last four years. I confirm that I pay Income Tax or Capital Gains Tax at least equal to the<br />
amount <strong>of</strong> tax which will be reclaimed on my subscription or on any donation.<br />
Signed<br />
Annual joint 1 membership @ £45 p.a.<br />
Joint 1 life membership @ £900<br />
Bobarts Group joint 1 membership @ £225 p.a.<br />
Date
16<br />
Botanic Garden News | No. 79<br />
The last word<br />
by<br />
Timothy<br />
Walker<br />
F<br />
erns such as Azolla that are featured<br />
in this edition’s “A few words” may<br />
be an ancient group <strong>of</strong> land plants<br />
with an illustrious past but they are<br />
new kids on the block compared with their<br />
nitrogen-fixing cyanobacteria lodgers. The<br />
cyanobacteria belong to a very ancient lineage<br />
<strong>of</strong> living organisms that have had an even<br />
more pr<strong>of</strong>ound influence on the Earth and its<br />
biology than has Azolla.<br />
Cyanobacteria, also known as blue-green<br />
algae or blue-green bacteria, have been<br />
described as “arguably the most successful<br />
organisms on Earth”. This claim can be<br />
Gunnera leaves in the Bog Garden cut and laid down to protect the rhizomes over winter<br />
supported by the fact that they are found in<br />
almost every habitat from seasonally dry,<br />
bare rocks in cold regions to hot springs<br />
where life should not exist. Moreover, fossil<br />
cyanobacteria have been dated at more than<br />
3,000 million years old. Part <strong>of</strong> their success<br />
has to be due to their ability to photosynthesise<br />
and fix atmospheric nitrogen. It is<br />
believed that their photosynthesis has made<br />
a significant contribution to current oxygen<br />
levels in the atmosphere.<br />
You might wonder why gardeners should<br />
be interested in these little organisms.<br />
The answer is simple: about 1,200 million<br />
years ago one <strong>of</strong> these photosynthesising<br />
cyanobacteria was engulfed by another<br />
single celled organism but rather than being<br />
digested and broken down, the cyanobacteria<br />
remained intact and was press ganged<br />
into a symbiosis. This cell was the first plant<br />
and had this endosymbiotic event not<br />
happened our gardens would be empty.<br />
Another species <strong>of</strong> nitrogen fixing cyanobacteria,<br />
Nostoc punciforme, lives in the vast<br />
leaves <strong>of</strong> Gunnera manicata which has grown<br />
bigger this year than anyone can remember.<br />
It is one <strong>of</strong> those odd quirks <strong>of</strong> biology that<br />
the tiny leaves <strong>of</strong> Azolla and the huge leaves<br />
<strong>of</strong> Gunnera both contain cyanobacteria.<br />
Perhaps cyanobacteria could be introduced<br />
into crop plants to replace the need for<br />
nitrogenous fertilizers<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> Botanic Garden<br />
November to February:<br />
open daily 9.00am to 4.30pm,<br />
last admission 4.15pm<br />
March, April, September & October:<br />
open daily 9.00am to 5.00pm,<br />
last admission 4.15pm<br />
May to August:<br />
open daily 9.00am to 6.00pm,<br />
last admission 5.15pm<br />
We are closed on Christmas Day<br />
and Good Friday<br />
No dogs allowed in the Garden<br />
(except assistance dogs)<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> Botanic Garden<br />
Rose Lane, <strong>Oxford</strong> OX1 4AZ<br />
Tel: 01865 286690<br />
E-mail: postmaster@obg.ox.ac.uk<br />
Web: www.botanic-garden.ox.ac.uk/<br />
Garden/obg-intro.html<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> <strong>Harcourt</strong> <strong>Arboretum</strong><br />
December to March:<br />
open Monday to Friday 10.00am to 4.00pm,<br />
last admission 3.30pm; closed weekends<br />
April to November:<br />
open daily 10.00am to 5.00pm,<br />
last admission 4.15pm<br />
We are closed 22nd December to 3rd January<br />
No dogs allowed in the <strong>Arboretum</strong><br />
(except assistance dogs)<br />
<strong>University</strong> <strong>of</strong> <strong>Oxford</strong> <strong>Harcourt</strong> <strong>Arboretum</strong><br />
Nuneham Courtenay OX44 9PX<br />
Tel: 01865 343501<br />
E-mail: postmaster@obg.ox.ac.uk<br />
Web: www.botanic-garden.ox.ac.uk/<br />
<strong>Harcourt</strong>/obg-harcourt-intro.html<br />
The Friends <strong>of</strong> <strong>Oxford</strong> Botanic Garden<br />
and <strong>Harcourt</strong> <strong>Arboretum</strong><br />
Rose Lane, <strong>Oxford</strong> OX1 4AZ<br />
All Friends’ enquiries, including those about<br />
Friends’ events, should be made to Liz<br />
Woolley, the Friends’ Administrator<br />
Tel: 01865 286690<br />
E-mail: secretary@fobg.org<br />
Web: www.botanic-garden.ox.ac.uk/<br />
Friends<br />
Please note that the Friends’ <strong>of</strong>fice is staffed<br />
only on Tuesdays and Wednesdays, between<br />
9.00am and 4.00pm. At other times urgent<br />
Friends’ enquiries will be dealt with by<br />
Garden staff.<br />
The newsletter is published by the <strong>University</strong> <strong>of</strong> <strong>Oxford</strong> Botanic Garden and is edited by Liz Woolley<br />
and Timothy Walker. The views expressed in articles are those <strong>of</strong> the authors and do not necessarily<br />
reflect the policy or views <strong>of</strong> the Visitors <strong>of</strong> the Botanic Garden.<br />
Design by Richard Boxall Design Associates