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L E U C O B R Y U M H am p e .
1. I . glaucum (L) Schimp.
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t t E L E U T H E R O P H Y L L E Æ .
L e a v e s in several rows, inserted horizontally, free from adnate
stipules.
Fam. 6. L EU C O B R Y A C EÆ .
Mosses o f a pale glaucous green colour, white and b rittle when dry,
growing in dense spongy tufts. L ea ve s in many rows, lanceolate, conca
ve, composed almost entirely o f the dilated nerve, which consists of
several layers o f empty parenchymatous cells, w ith th eir internal walls
perforated by foramina, and a central series o f 3-4-angled, chlorophyllose
duct-like cells. Capsule oblong, cernuous or e re c t ; peristome
resembling th a t o f Dicranum, o f i 5 or 8 te e th .— Inhabiting th e ground
or rotten wood.
The very striking plants referred to this family are almost entirely tropical,
and are remarkable for their pale colour, and the composite structure of their
leaves, compared by some authors to that of Sphagnum, to which however
they are not allied. The family was established by Hampe, and named
Leucophaneæ, but was altered by C. Mueller to Leucobryaceæ to accord
with the principal genus, and comprises about 65 species, nearly half belonging
to Leucohryum, the other genera being Leucophanes, SchistomUrium and Octo-
hlephamm. Our British species is the sole representative in Europe, and in
the other three quarters of the globe seems to be replaced by the equally
common Octoblepharum albidum. Lindberg reunites the family to Dicranaceæ,
as he finds that the leaves of D. albicans and longifolium in section, quite
resemble in structure those of Leucobryum. The leaves have generally been
described as nerveless, but it is more correct to regard them as consisting
almost entirely of nerve, for careful observation will show that near the base,
there is at the edges a very narrow but distinct lamina of only a single
stratum of narrow elongated cells. On the terminal leaves o f the ste.m of
female Leucohryum glaucum, it is common to find a minute tuft of radicular
tomentum developing a cluster of young plants, which falling to the ground
grow to a new colony, and thus compensate for the rarity of the fruit. Mr.
Barnes tells me that it is difficult to keep the lids on the capsules, as the
moss continues its growth even in the press, and to prevent this he
recommends those who are fortunate enough to find it in fruit, to dip it into
boiling water before pressing.
L E U C O B R Y U M H a m p e .
(Regensb. Bot. Zeit. 1837, b 2S2.)
Densely cæspitose mosses o f a whitish or glaucous colour, with
dichotomous and fa stig ia te ramification. C a lyp tra dimidiate, cucullate.
Capsule pachydermous, unequal, often strumose, p lica te when dry.