2. Wedge-shaped, compact }
1. Concatenate, exposed } Cystopus.
2. Spherical, concealed }
Tilletia, Tul.
Spores spherical, reticulated, proceeding from delicate branched threads.
Tilletia caries, Tul. Bunt; included within the germen; spores spherical, rather large, black.—On wheat, filling the grains with dark-coloured spores, fetid when crushed. Autumn. Very common. ([Plate V.] figs. 84-91.)
Ustilago, Link.
Plant deeply seated. Spores simple, springing from delicate threads, or in closely-packed cells, ultimately breaking up into a powdery mass.—Berk. Outl., p. 335.
Ustilago segetum, Ditm. Corn Smut; produced on the receptacle and rachis; epidermis soon ruptured; spores loose, minute, globose, black.—On the ears of corn and grasses. Autumn. Very common. ([Plate V.] figs. 98, 99.)
Ustilago urceolorum, Tul. Sedge Smut; produced on the glumes and utricles; epidermis soon bursting; spores in a compact mass, afterwards breaking up, globose, rather large, granulated.—Surrounding the seed of various Carices; as, Carex prœcox, stellulata, recurva, and pseudo-cyperus. Autumn. Not uncommon. ([Plate VI.] figs. 109-111.)