304 GYMNOSPORANGIUM 



GYMNOSPORANGIUM Hedw. fil. 



Eeteroecious. All fche sori subepidermal. 



Spermogones Bpherical, with ostiolar filaments. iEcidia 

 more or less elongated or tubular; peridium membranous, 

 rupturing by lateral slits; spores brown, with numerous evident 

 germ-pores. Teleuto-sori erumpent, naked, variously shaped, 

 gelatinous, expanding when moist; spores with long pedicels, 

 usually two-celled, generally with two pores (1 — 4) in each cell, 

 mostly near the septa: the cell-wall of the pedicels becomes 

 gelatinised. Germination by an ordinary basidiu m and roundish 

 basidiospores : these are thrown off with a jerk, at maturity, 

 like the spores of the Hymenomycetes (Coons, 1912). 



There are many species of Gymnosporangium in America 

 (Kern in X. American Flora gives :V1), of which only three 

 occur in Europe, and one or two in Japan. Several of these 

 have three, four, or five-celled teleutospores. The aecidia of the 

 Gymnosporangia are on Rosacese (except one on Hydrangeae) ; 

 the teleutospores are all on Cupressineae (Juniperus, Cupressus, 

 Chamaecyparis, Libocedrus), on which they often form swellings, 

 i.e. galls. But we get also one remarkable exception to this 

 rule in the autcecious species (the only one known) G. bermu- 

 dianum, which produces both its geeidia and its teleuto-sori on 

 Junipers (J. bermudiana and other species). 



1. Gymnosporangium clavariaeforme DC. 



Tremella clavariaeformis Jucq. Collect, ii. 174. 



Podioiuia Junqjirri Fr. ; Cooke, Handb. p. 510; Micr. Fung. p. 214. 



Roestelia lacerata Tul. ; Cooke, Handb. p. ">34 ; Micr. Fung. p. 193, 



pi. 2, f. 22—6. 

 /.'. carpophila Bagnis, Flofa^Jsiii. 317. 

 Gymnosporangium clavariaeforme DC. Flor. fr. ii. 217. Plowr. Ured. 



p. 233. Fischer, Ured. Schweiz, p. 383, f. 27"). Sacc. Svll. vii. 



737 p.p. Kern, in North Amer. Fl. vii. 202. Sydow, Monogr. 



iii. 59, f. 29. 



>'//- rmogones. Numerous, amphigenous, but chiefly epi- 

 phyllous, in little clusters on red spots, yellow, then dark-brown. 



