E R Y S IP H E P i s i .
P e a Leaf-mould.
C l a s s a n d O r d e r CRYPTOGAMIA FUNGI, Linn.—NA1. O r d . GASTROMYCI,
Link, Grev—P a r t o f FUNGI, Juss. ^
GENERIC c h a r a c t e r .
Sporangium minutum, globosum, carnosum, luteum, demum nigrum, sporidia magna
includens; hoA Jilamentis albis, numerosis, radiantibus, simplicibus, vel ramosis
instructum.
Sporangium minute, globose, carnose, yellow, at length black, inclosing
large sporidia, and furnished at the base with numerous, white, simple or
branched, radiating filaments.
SPECIFIC c h a r a c t e r .
E bysiphe Pisi ; sparsa ; Jilamentis plurimis, longisAmis, ramosis, tenuisdmis,
in pelliculam intertextis ; sporidiis ovalibus.
E. scattered on the leaves, petiols, &c.; filaments numerous, very long, branched,
exceedingly slender, interwoven into a pellicle; sporidia oval.
E rysiphe Pisi, De Cand. Fl. Franç. ed. S. v. 2. p. Ejusd. Sun. p. 57.
—Grev. Fl. Edin. p. 46l.
H a b . On Pisum sativum, the common garden Pea ; very frequent in Summer
and Autumn. Foxhall, Captain W a u c h . About Edinburgh, abundant.
Gregarious, on the stems, leaves and petioles; often so plentiful as to considerably
darken the surface of the leaves, while those parts not occupied
by the sporangia are covered with a fine white pellicle or web. Sporangia
minute, globose, yellow, then orange-brown or reddish, at length
b la ck ; smooth, umbilicated at the apex. Radiating fdaments slender,
very long, branched, exceedingly entangled and interwoven, very numerous.
Sporidia many, oval, containing 2 or 3 oval, very minute sporules.
E ry siph e of R e b e n t i s c h is perhaps one of the most extraordinary
genera of Gastromyci we are acquainted with. A ll
the species are found on living leaves, and are well known to
gardeners, nurserymen and farmers, by the general but improper
name of Mildew ; though other diseases have also received
vol.. I I I .