BSBINews - BSBI Archive - Botanical Society of the British Isles

Aliens - Planted aliens I Vegetative identification of Buddleja species 31
that a great deal more than is often admitted is
actually planted, I feel it is devaluing our
historical records of alien plants in our flora to
lump evidently planted individuals with
records for plants of the same species that
have succeeded in reproducing themselves, by
whatever means, out of cultivation. One can
argue of course about where cultivation begins
and ends, and it is not always easy to be sure
about status. But it seems we have let these
difficulties weigh so heavily that we have
given up even trying to distinguish the most
obvious cases. If, as can happen, recorders
then do not state that the record is clearly of
planted origin, we have no chance of picking
up and following the naturalisation of new
species in our flora. By all means record what
one finds planted, but surely we do not have to
make them part of our formal lists and claim
new British records every time a local Council
gets hold of some novelty to plant on a village
green or along the local bypass. If I go and
plant the Balearic endemic Carex rorulenta,
which thrives in my garden, onto the dry,
sunny bank in my local park, can I then write
that up as new to Britain? Surely not, yet in
effect that is what is happening. These
remarks come from someone as keen an alien
recorder as anyone, but I and all the alien plant
enthusiasts I have known would never claim
new records if they were not convinced the
plant they saw had got there other than by the
deliberate hand of man. It may seem a fine
line to draw but I find fellow enthusiasts have
no trouble understanding its value. Without it
one might just as well list everything you grow
in the garden, and if a species is missing from
your county flora, just go out and plant it on a
local roadside and hey presto you can put it on
your list.
Indeed I think this uncritical attitude towards
alien records has led many into a ready acceptance
that it does not really matter how any
plant gets to where we find them and thus the
recent trend to promote so-called wild flower
mixes being sown everywhere, whether of
supposed local origin or not, is again making
a nonsense of plant distributions and our
ability to interpret and draw conclusions about
their ecology. We should not be condoning
such practices in the countryside.
Vegetative identification of Buddleja species
JOHN POLAND, 91 Ethelburt Ave., Southampton, Hants S016 3DF
(jpp197@alumni.soton.ac.uk)
Since the publication of the Vegetative Key to
the British Flora (Poland & Clement, 2009),
inevitably a few more vegetative characters
for separating similar species have come to
light. Some of these include the identification
of naturalised Buddleja species. Although
everyone will be familiar with B. davidii
(Butterfly-bush), fewer may be familiar with
the widely planted B. globosa (Orange-balltree)
unless in flower. Below is a simple
vegetative key based primarily on the rugosity
('wrinkliness') of the leaves. The hybrid
(B. weyeriana (Weyer's Butterfly-bush)) is
intermediate in all respects (including flower
characters not included in this key). A third
species of frequently planted Buddleja:
B. alternifolia (Alternate-leaved Butterflybush),
is quite distinct in having alternate
leaves, as the name suggests, and consequently
is not keyed out here. B. fallowiana,
B. lindleyana and B. spectabilis are considered
too rare to be included.
Shrub evergreen (or ± so). Lvs 0pp., toothed, white- or yellow-felted below with stellate
hairs
.Lvs strongly rugose above, with 3° veins raised below, yellow- or white-felted below,
crenate. Twigs mostly without interpetiolar stipules ....................................... Buddleja globosa
.Lvs not or weakly rugose above, with 3° veins not or weakly raised below, white-felted
below, serrate. Twigs mostly with interpetiolar stipules .................................. Buddleja davidii