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L I C H E N leucomelos.
Black-haired, Lichen.
b b
CRYPTOGAM1A Algee.
Gen. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Leafy, membranous, spreading, smooth,
white on both sides; channelled and powdery
beneath: segments linear, fringed with long, black,
very slender hairs. Shields stalked, blueish-black,
with a white radiating border.
Syn. Lichen leucomelos. Linn. Sp. PL 1613. Ach.
Prodr. 181. Swartz. Obs. 4 0 /. t. 11. f . 3.
Lichenoides angustifolium planum, crinibus nigris.
jyill. Muse. 156. t. 2 1 . ƒ 50.
Parmelia leucomela. Ach. Melh. 256.
D is c o v e r e d by Mr. W. J. Hooker at Babbicombe in
Devonshire last February. This species had never before been
met with in Britain, but is a native of the West Indies, and of
St. Helena. The fronds grow in dense lax tufts, spreading
amongst thyme, &c. in heathy places, and are known by their
generally very pure white colour and great smoothness above,
contrasted with their remarkably long, slender, coal-black,
simple or branched, marginal hairs. Sometimes there is a grey
or smoky tinge. The breadth of the segments varies much.
The under side is channelled and mealy, always snow-white.
The elegant shields were not found by Mr. Hooker. We have
them on specimens gathered by Mr. Menzies in St. Helena.
They are lateral, scattered, on short stalks; the disk flat,
greyish, surrounded with a white, leafy, radiating margin,
sometimes bearing black hairs like those of the frond.