A biological study of Durvillaea antarctica (Chamisso) Hariot and D ...

43
cortex (Figs 3.3a and 3.4e). Otherwise it bore a close resemblance
to the other sections- Differences between the tlilO D, haY"1Jeyi
specimens were, if anything, greater than the differences between the
D. ha:t'veyi lectotype, and the two D. utiZ-is specimens.
There \~as
a marked similarity between the lamina sections of
these four Hooker specimens and srn.all cape and thonged form D.
anta:.t>CJtic:a from New Zealand and Chile (1"igs 3.4 and 3.5) _
The
medulla of the New Zealand and Chilean plants also contained numerous
vacuole--like spaces. and Has separated into L-wo plates of hyphae
(running predominantly longitudinally and horizontally) by a central
zone of highly branched" loosely interweaving hyphaeo
Hyphal
cell \\l'alls were highly gelatinised,
These comparisons strongly
suggest that specimens annotated by Hooker as D. harveyi are immature
cape form D. anta:r'etiea, If there is another species, in a.ddition
to D. antarctica, growing in the Mage11anic region of South America
or the Falkland Islands, then presumably this fact ... Ionld not escape
the attention of other botanists who collected in the same areas
as Hooker 0
Cunningham (1871:294) stated that D. harveyi and Do utilis grew
together in the strait of Magellan, and that D. utilis fronds !;Jere
honeycombed Nhereas D. harveyi fronds ",ere noto Dickie (1879: 55)
said that on Kerguelen Island D. harveyi grew in places more e}~os8d
than those occupied by D, utiZis. Harlot (1889:54) claimed ~~at
D. harveyi was the honeycombed species. Cotton (1915), quoting Mrs
Valentine. (resident on the Falklands and very familiar tvith marine
algae). stated (p.166) that the colour and the habita.t of the h/o
species was the same, and that all plants when dried
the
appeal:"?nce of honeycomb.
Morphological variation of D. utilis I descJ:'iberl by Areschollg
(1854:16[342]) was recognised by Skottsberg( \~ho ptoposed that the
poorly divided form should be called D. harveyi iJnd the highly
divided form D. antarcti()a. He stated (1921:54) "Typica.l D. harveyi
is so utterly unlike antarctica that nobody \"ould be inclined to
unite tbem under the same specific name. still we ll\ust cons ider
the possibility of regarding all forms as belonging to one
adapted to various external conditions. Or, they may be hybrids.
With my present knowledge of these plants r do not, howevex, find
suf'ficient reasons to suppress D, harveyi"o It is highly
probable that Hooker also decided tho.t the dissinlilari ty of the
extreme eCOlogical forms \"as such t.hai: they should he
d o.s