Feb., 1913.] The Classification of Plants, VIII. 77 



21. Ascoma more or less completely closed at first, opening free at or 

 before maturity, and plane, concave, or rarely convex. 22. 



21. Ascoma open from the first, normally convex and commonly with the 



surface pitted or with gyrose furrows. Helvellales. 



22. Ascoma long enclosed in a tough covering which is torn open at the 



maturity of the spores. 23. 



22. Ascoma soon becoming free, without special covering; mostly fleshy 



cuplike fungi. Pezizales. 



23. Ascoma mostly elongate, the cones opening by a longitudinal fissure. 



Hysteriales. 



23. Ascoma roundish, the cover rupturing by radiating or stellate fissures. 



Phacidiales. 



24. Asci arranged at different levels in the perithecium or in a hymenium 



lining enclosed cavities. Aspergilleae. 25. 



24. Asci in fascicles arising from a common level. 26. 



25. Asci arranged at different levels, sometimes forming skein-like masses. 



Aspergillales. 



25. Asci in a definite flat hymenium lining cavities, permanently enclosed; 



fruiting body mostly subterranean. Tuberales. 



26. Cleistothecia globose, scattered, without apparent ostiole, usually 



with appendages, mostly attached to an apparent mycelium or 

 membrane; in one family flat shield-shaped perithecia with ostiole 

 present. Perisporiales. 



26. Perithecia typical with distinct ostiole. 27. 



27. Perithecia (and stroma if present) fleshy or membranous, bright- 



colored (white, red or blue). Hypocreales. 



27. Perithecia (and stroma if present) hardened, never fleshy, rarely 



membranous, dark-colored (black or dark brown). 28. 



28. Walls of the perithecia scarcely distinguishable from the stroma. 



Dothideales. 



28. Perithecia with distinct walls either free or imbedded in a stroma. 



Sphaeriales. 



29. Conidia borne on short stalks in pycnidia. Sphaeropsidales. 



29. Conidia superficial, borne on loose or innate hyphae; no true pycnidia 



present. 30. 



30. Hyphae somewhat superficial, often floccose. Moniliales. 



30. Hyphae innate with the matrix; parasitic; the conidia borne on a 



pseudo-pycnidium, formed from the altered tissue of the host. 



Melanconiales. 



—31— 



31. Chlamydospores produced in the ovularies, leaves or stems of the host, 



usually black, not stalked. 32. 



31. Chlamydospores (teleutospores) usually stalked, producing black or 



brown pustules under the epidermis of leaves or stems; often devel- 

 oping on the same or on a different host clusters of cup-like or crater- 

 like aecidia with spores formed in chains inside of a membranous 

 pseudoperidium. Uredinales. 



32. Chlamydospores developing a several-celled basidium (promycelium) 



which bears the spores at the sides of the cells. Ustilaginales. 



32. Chlamydospores developing a nonseptate basidium which bears the 



spores at the apex. Tilletiales. 



33. Fungi symbiotic with algal cells. Hymenolichenes. Corales. 



33. Fungi without helotic algae in their bodies. 34. 



34. Plants gelatinous, basidia divided, transversely or longitudinally or 



deeply two-forked. Protobasidiae. 35. 



34. Plants fleshy, coriaceous, woody, or rarely somewhat gelatinous; 



basidia nonseptate. 36. 



35. Basidia transversely septate. Auriculariales. 



