Cyathus Vernicosus, Another Tetrapolar Bird's Nest Fungus

SUMMARY 1. Basidiospores of Cyathus vernicosus were germinated one year after collection by subjecting them to a temperature of 40° C. for 48 hrs. in distilled water suspension.2. Sixty single-spore mycelia were cultured, of which 29 were used in a study of heterothallism.3. Single-spore mycelia are haploid. The mycelia are quite uniformly white and fluffy, an occasional one showing grey-brown coloration.4. When paired, haploid mycelia fall into four mating-type groups with uneven distribution of mycelia in the groups. The fungus is heterothallic and tetrapolar.5. Diploid hyphae bear clamp connections and tend to become aggregated into cords upon which fruit body rudiments arise.6. Diploid mycelia were induced to fruit only by covering cultures on agar slants with an inch of sterile soil.7. Each fruit body of C. vernicosus has an “emplacement” or mass of basal hyphae which becomes compacted into a solid ball within the soil. This structure is similar to the emplacements of C. striatus and C. stercoreus.8. The epiphragm of C. vernicosus ruptures most frequently in a circumscissile manner and withdraws to one side of the cup as a shrunken disk.