III. Class Basidiomycetes. (The basidium series.)
1. SUBCLASS HEMIBASIDIOMYCETES.
456. Order Ustilaginales (Ustilagineæ).—This order includes the well-known smuts on corn, wheat, oats, etc. (Ustilago, Tilletia, etc.).
2. SUBCLASS ÆCIDIOMYCETES.
457. Order Uredinales[23] (Uredineæ).—This order includes the parasitic fungi known as rusts. Examples: wheat rust ([Chapter XX]), the cedar apple, etc.
The true Basidiomycetes include the following orders:
3. SUBCLASS PROTOBASIDIOMYCETES.
458. Order Auriculariales.[24]—This order includes trembling fungi in which the basidium is long and divided transversely into usually four cells (example, Auricularia), and similar forms. Pilacre petersii on dead wood represents an angiocarpous form.
459. Order Tremellales (Tremellineæ), trembling or gelatinous fungi with the globose basidium divided longitudinally into four cells (Tremella).
4. SUBCLASS EUBASIDIOMYCETES.