THE
JOURNAL OF BOTANY,
BRITISH AND FOREIGN.
Original Articles.
AGARICUS (LEPIOTA) GEORGINÆ; A NEW SPECIES OF AGARICUS.
By Worthington G. Smith, F.L.S.
(Plate CXII.)
This elegant and curious Lepiota differs from any species hitherto described. Its specific characters are sufficient to distinguish it from the other Lepiotæ, but with the exception of one or two plants of the group, it may be readily recognized by its parasitic habit, the members of the subgenus, with the exceptions referred to, being all terrestrial. It is probably exotic, perhaps of Eastern origin, as I have not met with it elsewhere than in the cool fernery at Messrs. Veitch and Sons' Nursery, at Chelsea. It does not come up in the stoves and hothouses like some exotic species of Lepiota, but is confined exclusively to the cool fernery, where it may be found all through the year on different species of Mosses which grow amongst British Ferns and other hardy plants. Judging from its habitat, it seems reasonable to suppose that it may have been introduced with some of Messrs. Veitch's extensive importations from Japan and neighbouring territories.
It comes into Fries's section "Clypeolarii," and its nearest allies are A. Badhami, B. and Br., and A. Meleagris, Sow. One of its most striking peculiarities is its instantaneous change of colour from snow-white to blood-red when touched. So sensitive is it, that when gently laid with the pileus downwards on paper, the part of the surface in contact with the paper immediately changes colour, and if rolled over, it leaves a brilliant carmine stain wherever it touches. The portions of the gills nearest the stem are usually crimson, merely from accidentally coming in contact with the stem to which they are closely approximated though free. The red colour ultimately becomes dark brown, and after the lapse of a few hours from gathering, the Agaric loses its property of changing colour. Several other Lepiotæ change colour, but none have the remarkable sensitiveness of this species.
Agaricus (Lepiotæ) Georginæ, sp.nov. Pileus white, slightly fleshy, fragile, at first campanulate, then expanded, 12 in. to 1 in. across, covered with a minute, deuse, viscid pruinosity which, as well as the white flesh, instantly changes to crimson when touched; margin at length striate. Stem slightly attenuated upwards, 1 in. to 2 in. long, also covered externally with minute
VOL. IX. [JANUARY 1, 1871.]B
