y
i
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This is a very curious plant, and has given rise to much
uncertainty respecting its extraordinary root. Until P e r s o o n
published his Synopsis Fungoriim, authors had supposed this
tuberous root to be really a part of the plant ; but P e r s o o n
considered it as another plant, and called it Sclerotiumfungo-
rum. Subsequent writers do not seem to have made up their
minds on the subject, generally contenting themselves with
quoting P e r s o o n ’s observations. D e C a n d o l l e , in a memoir
on the genus Sclerotium, in the Mémoires du Muséum
d ’Histoire Naturelle, v. ii. p. 401., describes the tuber as a
true Sclerotium. Lastly, F r i e s , in his Systema Mycologi-
cum, affirms the stem of the agaric to terminate in Sclerotium
cornutum, {S.fungorum of P e r s o o n ) .
I have examined the root of this curious agaric with great
attention, and am rather inclined to believe it a part of the
plant. Tn every specimen I have seen, the agaric invariably
rises from the smallest extremity of the tuber, never from the
side ; and under the microscope, I have traced a continuation
of the substance of the stem into the tuber, as perfectly as my
dissecting instruments would allow me to do. Besides, I am
not aware tbat the tuber has ever been found without the agaric,
or at least traces of its having been attached to one. B u l -
L iA R D has a figure of one tuber giving rise to several stems,
which, if correct, rather strengthens the idea of its not being a
distinct substance ; and D e C a n d o l l e , in the 2d volume of
the Flore Française, p. 178., gives so minute a detail of the
growth of the tuber, from the size of a petite grain e ou tubercle,
to its full dimensions, along with the agaric, in the
form of a file t menu, hlanc, et surmonté d ’une petite tête, that
it is difficult to conceive how two different plants should so
constantly be found together, and invariably attached in the
same manner, i. e. at the projecting points or extremities only.
Agaricus alumnus of B o l t o n 1 have little doubt belongs
to our present species, though he says it wants the tuber : this
may easily be conceived to have been detached in gathering it.
Fig. 1. Plants o f Agaricus tuberosus. Fig. 2. A section.