1825. Perichcena is most nearly allied to Lycogala and L icea.
From the former it differs in its simple peridium ; for
F r i e s considers the true Lycogaloe to have a double peridium,
the outer one passing away into warts, while the inner
one remains entire and bursts at the apex. From Licea it differs
in having filaments lying among the sporidia. I t likewise
differs from both Lycogala and Licea in bursting horizontally
into two regular portions. Both the figures of B u l l i a r d and
S o w e r b y furnish a very imperfect representation of our plant.
That of B u l l i a r d is almost black, and that of S o w e r b y not
only much too dark, but of an oval figure. I cannot hut entertain
a strong suspicion that the latter is another plant; and therefore,
that British authors who have followed S o w e r b y are unacquainted
with the true Perichcena populina. I t is possible,
however, that the var. |3 of A l b e r t i n i and S c h w e i n i t z may
have been mistaken for it. This is described as a distinct species
by F r i e s , “ P. abietina, hypothallo fucescenti, peridiis badio-
nigris, sporidiis l ut e i s and it is not unlikely the subjacent
membrane may have been overlooked.
Fig. I. P . populina, natural size. Fig. 2. A group o f plants. Fig. 3. Sporidia
and Jilaments ; magnified.