t p
R A D U L U M ORBICULARE.
Circular Radulum.
\
C l a s s a n d O r d e h CRYPTOGAMIA FUNGI, Lmn.—IIYM ENOM YC E TE S .
O k d . I. PILEATI, Fries.
G EN E R IC CHARAC TER .
Hymenium interruptum, hinc inde subidis hibercuhsum.
Hymenium interrupted, here and there tuberculated with subulate processes.
S P E C IF IC CHARAC TER .
Radulum orbiculare ; orhiculatum, resupinatnm, albo-lutescens, margine bys-
sino, aculeis difformihus, apicibus villosis.
R. circular, resupinate, w hite, becoming yellowish, the margins byssoid, the
processes irregular in form, villose at the apex.
Radulum o rbicula re . Fries, Syst. Orb. Veg. 1. p. 81.
H ydnum Radula, Fries, Obs. Mycol. 2. p. 271-—Syst. Myc. v. 1. p. 423.
H ydnum spathulatum, Grev. Fl. Fdin. p. 406. An Auct. ?
Had. On the trunks of dead Birch-trees (Betula alba). Autumn, winter,
and spring. Appin, Captain Carmichael. Auchindenny woods, near
Edinburgh.
Pileus entirely resupinate, one to several inches in diameter, at first circular,
afterwards irregular, and often confinent, of a white colour, mostly
changing (especially in the centre) to a pale orange-yellow ; margin filamentous,
radiating, somewhat raised, or rath e r thickened. Hymenium
composed o f processes, irregularly distributed over the surface o f
the pileus, and more or less distant. They are singularly variable in
their form, b u t are mostly 2-3 lines in length, slightly compressed, and
somewhat broader at the apex than at the base. Often several are confluent,
and altogether deformed. At their apex, they are generally entire,
and sometimes naked, b u t more frequently villose. In regard to
direction, I have seen them both erect and oblique, or even closely ap-
pressed.
S o v ery near does th is fu n g u s ran g e (in d e sc r ip tion a t lea st)
w ith Hydnum spathulatum o f F r i e s (Sistotrema spatlm-
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