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UREDO POLYGONOHÜM.
Polygonum Uredo.
C l a s s a n d O b d e b C R Y P T O G A M IA F U N G I , A im — NAT . O b d . G A S T R O M Y C I ,
GrCT— E P I P H Y T A E , L in k .
G EN ERIC CHARACTER.
Peridium verum 0. Sporidia non septata, nuda, libera. Plantuke “ sub epidermide
foliorum herbacearum orto; et epidermide rupta facile disperses,'’ IXl.
Epidermis peridio simillima.
No true peridium. Sporidia unilocular, naked, free, bursting through the
epidermis of the leaves of herbaceous plants, and easily dispersed; epidermis
resembling a true peridium.
S P E C IF IC CHARACTER.
U redo Polygonorum; plerumque hypopliylla, orbiculata, rarius in circolo dis-
posita, palUdo-Jusca, sporidiis glohosis.
U. mostly hypophyllous, orbicular, sometimes disposed in a circular manner,
pale brown, the sporules globose.
U redo Polygonorum, De Cand. Fl.'Frauf. ed. 3. v. 6. p. 71. P i Ban, 1 .1318.
—Gren. FI. Fdin. ined.
U redo Beta;, var. /3/3, Alb. et Schmein. Conspect. Fung. p. 358.
U r e d o vagans, y, DC. Syn. F i Gali p. 47.
H ab. On the leaves of Polygonum amphibium, P. convolvulus, and P. avieu-
larics. Summer and autumn, very frequent.
Scattered or arranged in small circles, of a pale brown colour, mostly round,
but when growing in a circle (in which case there is always a central
one), the little tufts are o f an oval or oblong figure. Sporules numerous,
globular, some o f them furnished with minute pedicels.
This Uredo seems to be common to a number of the Poly-
goni, and is therefore well named by D e C a n d o l l e . Whether
physical properties, or a peculiar organization in natural
families of phsenogainous vegetables, have any influence upon
the external characters of such plants as are parasitic upon
them, IS difficult to decide, yet highly probable. It is certain.