358 MELAMPSORIDIUM 
MELAMPSORIDIUM Klebahn. 
aie 2 
Hetercecious. id 
Teleutospores one-celled, with brownish membrane, united 
into flat waxy crusts, but each little group starts almost always 
directly beneath a stoma. Uredo-sori surrounded by a hemi- 
spherical peridium which opens by an apical pore, often begin- 
ning beneath a stoma; uredospores abstricted singly, more or 
less smooth at one end, with indistinct germ-pores, not mixed 
with capitate paraphyses. Atcidia with a well-developed inflated 
peridium. Spermogones subcuticular, other sori subepidermal. 
This genus is, in some respects, as closely allied to Puccint- 
astrum as to Melampsora, or rather more to the former than to 
the latter. . 
Melampsoridium betulinum Kleb. 
Melampsora betulina Desm. ;XCooke, Handb. p. 522, f. 212 (misnamed 
winter spores); Micr.”Fung. p. 219, pl. 9, f. 189, 190. ‘Plowr. 
Ured. p. 248. Mace. Syll. vii. 592. 
Melampsoridium betulinum Wleb. Zeitschr. f. Pflanzenkr. 1899, p. 21 
(see also 1891, p. 1380); Wirtswechs. Rostp. p. 401. VPischer,” 
Ured. Schweiz, p. 512, f. 320. 
Uredo populina var. betulina P. ys p. 219. 
fe 
Acidiospores. Aicidia hypophyllous, single or in longitu- 
Fig. 267. M. betulinum. w, peridium of uredo-sorus, viewed from above, 
showing the point at which it will dehisce, x 300; b, uredospores, x 600. 
dinal rows parallel to the mid-rib, small, oval or oblong, 1—14 
mm. long, clear reddish-orange, with irregularly torn margin; 
