1488 * ARBORETUM AND FRUTICETUM. PART IIl. 
In these instances, the pedicel is often a little longer, and the capsules more 
slender. j 
“The colour of the young shoots varies greatly, often so much as to cause 
the varieties to appear distinct species. The branchlets of S. alba are either 
brown, or, as in the var. vitellina, of a yolk-of-egg or a red brick colour; and 
there is a different shade of yolk-of-egg colour in S. répens, and S. rosmarini- 
folia (S. lee‘ta Schultz). Many species, when carefully examined, will be found 
to vary in colour, though only to a small extent. The branches of S, purpurea 
are of a coral colour, rarely of a dark yellow, and sometimes white, covered 
with a reddish bloom. S.amygdalina has the shoots sometimes of a brownish 
yellow, and sometimes of a brownish black. ; 
“‘ The form of the leaves in the same species, and even in the same plant, can 
never be depended upon. InS. phylicifolia, S. myrtilloides, S, arbuscula, and 
S. répens, they vary from narrow-lanceolate and being attenuated towards 
the base, in the three last-named species, to roundish-ovate and being cordate- 
emarginate at the base. In some species, the form of the leaves is almost 
always the same, as in S. viminalis, S. incana, and S. hippophaefolia. Ia 
other species, the leaves vary ; being serrated or entire, green or hoary on the 
under surface, and glabrous or hairy, on the same plant. The same variation is 
common on the exterior of the ovaries; which, in S. phylicifolia, are some- 
times glabrous, and sometimes hairy; some individuals of this species having 
half the ovary hairy, and the other half glabrous; while in others there is only 
a hairy or downy line. In certain species, however, these variations are never 
found, or very rarely ; although in S. viminalis ovaries partly naked, and 
partly downy, occur. The brown tip of the bracteas of the flowers, in some 
species, turns paler; and in others red, or even purple; which is another cause 
of uncertainty in specific distinctions. The bracteas are sometimes obovate, 
and only half the length of the ovary; and sometimes, in the same Species, 
lanceolate, and reaching as far as the style. The style and stigma likewise 
vary in length, and are occasionally more or less cleft; yet both these organs 
afford most useful characteristics. The style often appears shorter from being 
hidden by the long hairs of the ovary. Stigmas of a rose colour, and of a 
yellow colour, have been found in the same species. The stipules vary in size, 
but never in form; hence they afford the very best characteristics for distin- 
guishing species. In no species can these be said to be wanting ; and, though 
on old plants they are often not seen, such plants, when cut down, send up : 
young shoots which produce leaves attended by stipules of an extraordinary) 
size. The buds are always 1-valved; and the valves are often cleft at the tip, : 
and sometimes as far asthe base; though sometimes, on the same individual, 
they are undivided. The folding of the leaves in the bud is, most probably, 
constant, although different in the various species: but this I cannot affirm 
as certain, not having examined the leaf buds of a sufficient number of species. 
“The variation of the different parts is not the only difficulty with which the 
botanical student, in this cin has to contend: the great number of hy- 
| 
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1 
brids, the existence of whi 1 the genus Salix no one can doubt, is another 
obstacle. Nobody will accu e of arrogance in assuming to know S. ribra 
and S. viminalis. On the banks of the Rednitz, near Erlangen, there are many 
thousand trees of these two species ; and, at the same time, many intermediate 
forms, which I can refer to neither species. The catkins of these afford no 
distinguishing marks; for what seem at one time to belong to the former 
species, at another time appear more nearly allied to the latter.” Koch con 
cludes by stating that, in his Commentary, the species have been arranged i 
10 groups; and that no kind has been admitted as a species that he has nc 
himself seen and examined. He has added but few varieties, “ although an 
immense number of no importance might have been adduced ; being convin 
from daily observation and experience, that the multiplication of varieties, in- 
one of rendering any intricate genus more clear, only involves it in a greater _ 
ifficulty.” 4 Sa 4 
The Head of Koch, besides being identified with those of the Species — 
