448 APPENDIX 



Pileus. Cap of a mushroom. 



Pro mycelium. A special type 'of germtube of the rust and smut fungi. 



It forms a basidium with basidiospores or sporidia. 

 Protoplasm. Living substance of an organism. 



Pycnidium (pycnidia). Closed, globose or flask-shaped, asexual spore- 

 containing body. See acervulus. 

 Pycnosclerotium (pycnosclerotia). Sclerotial body resembling a 



pycnidium which may become a perithecium. 



Pycnospore. An asexual spore a conidium borne in a pycnidium. 

 Rhizomorph. A root-like, branched strand of fungus hyphse. 

 Saprophyte. An organism living on dead material. 

 Sap-wood. Living wood next to the bark which contains much of the 



sap. 

 Sclerotium (sclerotia). A tuber-like vegetative structure of certain 



fungi consisting of a densely woven mass of hyphse which may 



rest for a long period. 



Seta (setae). A bristle, or bristle-like body. 



Sporangium (sporangia). Asexual spore-containing sac. Not in- 

 closed. 

 Spore. A cell capable of reproducing a plant like the parent. A 



structure belonging to the fungi and related plants. Corresponds 



in function to a seed. 

 Sporidium (sporidia). Diminutive of spore. Usually applied to spores 



of the rust or smut fungi borne on the promycelium. 

 Stoma (stomata). A minute opening in the epidermis of stems, leaves 



and fruits which admits free exchange of gases between the interior 



and exterior. 

 Stroma (stromata). A fruiting, or spore-bearing, cushion composed of 



mycelium entirely, or of mycelium and host-tissue. 

 Swarm-spore. Motile spore. 

 Teliospore. Chlamydospore of a rust fungus which usually rests. 



Produces a promycelium on germination. 

 Telium (telia). Sorus in which teliospores are borne. 

 Uredinium (uredinia). Sorus in which uredospores are borne. 

 Uredospore. Spore of a rust fungus which perpetuates it throughout 



the summer. Produces a germtube on germination. 

 Veil. A special membranous envelope in mushrooms, which at first 



covers the gills. Later remnants of it may be seen on the stalk or 



stipe. 



