D O T H ID E A ALNEA.
Alder-leaf Dothidea.
S P E C IF IC CHARACTER.
Dothidea alnea ; amphigena, regulariter sparsa, subrotunda, nigra, nitida, col-
lapsa, nigoso-plicata.
D. on both sides of the leaf, regularly scattered, roundish, black, shining,
collapsed, rugose and plicate.
Dothidea alnea, Fries, Syst. Mycol. v. 2. p. 564.
Xyloma aliieum, Fers. Syn. p. 108.—Alb. et Schmein. p. 66.—Wahl. Fl. Lapp.
p. 524.—B e Cand. Syn. Fl. Gall. p. 63.—Ejusd. in Mus. d’Hist. Nat. v. 3.
No. 21.—Moug. et Nestl. St. Exsicc. No. 78.—Schmein. Syti. Fung. Carol.
No. 286.—Fries, Scl. Suec. Exsicc. No. 288.—Hoole. Fl. Scot. pt. 2. p. 9-
Furt. Midi. Fl. v. 3. p. 318.—Grev. Fl. Edin, p. 368.
H ab. On the leaves (while yet green) o f the common Alder ( Alnus glutinosa
J , not unfrequent, throughout Great Britain. Autumn.
Minute, very regularly scattered over a p a rt or the whole surface of the
leaf, black, somewhat shining, roundish, depressed, collapsed and ru gose.
Spondes oblong, very numerous, naked, in a gelatinous mass.
I cannot perceive the least trace of an opening in this species
at any stage of its growth, and the interior is filled with a
gelatinous mass of numerous oblong sporules, wholly unmixed
with filaments or tubular thee® of any kind, in which respect
it seems to differ from the character of the genus, as laid down
by my indefatigable friend M. F r i e s : in other respects it
agrees sufficiently 5Yell. Both the above species are, I believe,
figured for the first time.
Fig. 2. a, Dothidea alnea, nat. size, b, Flants magnified, c. One divided,
ditto, d. Another ditto, with the mass o f sporules pressed out. e, Sporules.
. 't