ACTINOTHYRIUM G r a m in i s ;
Minute black Actinothyrium.
iip
4!
C l a s s a n d O h d e r CRYPTOGAMIA FUNGI, T ìo t— N a t . O r d . H YPOXYLA,
De Cand.
G EN ERIC CHARACTER.
Perithecium scutiforme, radiato-fbrosum, subtus loeve. Sporidia fusformia.
Perithecium shield-shaped, composed of radiating fibres, smooth beneath-
Sporidia fusiform.
S PEC IF IC CHARACTER.
A c t i n o t h y r i u m Graminls ; ....................
A c t i n o t h y r i u m Graminis, Kunze, Mykol. Hefte, 2. p. 81. t. 2. f. 3.—Deutschl.
Schmaem. No. 183 Fries, Sclerom. Suec. No. 64.—Moug. et Nestl. Stirp.
Fxsicc. No. 657.—Fries, Syst. v.2. p. 597-
H a b . On the leaves and culms of various grasses, in the spring, frequent.
Common about Edinburgh. I t has been obligingly communicated from
England by W. C. T r e v e l y a n , Esq.
To the naked eye, a clear, very black spot, about one-third of a line in
breadth, is all the appearance made by this curious minute plant. The
spots (perithecia) are irregularly gregarious, sometimes confluent. Under
the microscope, the structure is obvious. The perithecia are orbicular,
adnate with the body on which they grow, plane towards
the margin, b u t thickening somewhat towards the centre, where they
are obtusely umbonate. The outer surface is a mass of stout fibres
radiating from the centre to the circumference, somewhat twisted and
interlaced, except at the margin, where they are free, and terminate obtusely.
The under surface of the perithecia is plane, even, and of a rather
pale colour, th e attachment chiefly in the centre. On making a
vertical section, we find a considerable portion of the circumference to
consist of nothing b u t a stratum of fibres ; b u t towards the centre is a
shallow cavity, filled with a gelatinous substance, composed entirely, or
nearly so, of slender, curved, fusiform sporidia.
This singular little production, first published by Professor
K u n z e , seems to be more allied to Leptostroma than any
other genus, and accordingly M . F r i e s has placed it between
Excipula and that genus. I have never been able to ascer-
VOL. IV.