Cystopus.
Receptacle consisting of thick branched threads; conidia concatenate, at length separating; oospores deeply seated on the mycelium.
Cystopus candidus, Lév. Crucifer White Rust; conidia equal, globose; membrane equal, ochraceous; oospores subglobose, epispore yellowish-brown, with irregular obtuse warts; warts solid.—On Shepherd’s-purse, Cabbages, and other Cruciferæ. Summer. Very common. ([Plate X.] figs. 198-200, 205-207.)
Cystopus cubicus, Str. Goatsbeard White Rust; conidia unequal; terminal cell sterile, larger than the rest; membrane thickened, ochraceous, rarely yellowish; fertile cells shortly cylindrical; membrane hyaline; oospores globose; epispore brown, verrucose; warts hollow, round, or irregular.—On goatsbeard, salsify, and scorzonera. Summer and autumn. Common. ([Plate X.] figs. 201, 202, 210.)
Cystopus Lepigoni, De By. Sandwort White Rust; conidia unequal; terminal cell sterile, globose; membrane thickened; fertile cells subglobose or cylindrical; membrane hyaline; oospores globose; epispore brown, tubercles minute, irregular, very convex, often resembling spines.—On Spergutaria rubra. Swanscombe Marshes, September, 1864. (R. G. Keeley.)