II 



Order I. HYMENOMYCETES 

 Fam. I. AGARICACE^ 



Hymenium spread over the surface of radiating gills, the axis a 

 stem, rarely a point, usually central, sometimes lateral. In some 

 forms the young fungus is entirely enclosed in a primary or universal 

 veil (fig. 10 B). During growth, as the stem elongates, the veil is 

 ruptured, the lower portion called the volva (Vo.) remaining as a 

 sheath round the base of the stem, while the upper portion, still 

 attached to the pileus, is torn into fragments as the latter 

 expands (u.v.). In some species a secondary or partial veil is also 

 present in the earlier stages, spreading from the upper part of the 

 stem to the edge of the pileus. This veil is finally ruptured, and 

 partly persists as a ring or annulus (A), encircling the stem. Contains 

 two-thirds of the whole Basidiomycetes. Species 1 — 1455 



Key to the Genera. 



In using the key for the determination of the genus the following 

 characters must be ascertained : — i. Colour of the spores. 2. Nature 

 of the substance, whether fleshy, putrescent, deliquescent or coriaceous. 

 3. Whether the hymenophore is distinct from the stem, or confluent 

 and homogeneous with it. 4. Nature of the pileus, whether dry, 

 viscid, silky, etc. 5. Nature of the stem, whether simple, annulate 

 or volvate, and whether it is homogeneous with the pileus, or 

 heterogeneous with a cartilaginous bark. 6. Nature of the gills and 

 their attachment to the stem. 



I. Spores white. 



A. Plant fleshy, more or less firm, not deliquescent or 

 coriaceous. 

 Hymenophore distinct from the fleshy stem. 



Pileus bearing warts or patches free from the cuticle. 



Stem volvate and annulate 1 Amanita. 



Stem volvate 2 Amanitopsis. 



Pileus pulverulent, smooth or scaly ; scales, when 

 present, concrete with the cuticle. 



Stem annulate 3 Lepiota. 



Stem simple 4 Hiatula. 



Hymenophore confluent and homogeneous with the 

 fleshy stem. 

 Stem without cartilaginous bark. 



Stem central (some of the plants under 50 are 

 stemless). 

 Annulate 5 Armillaria. 



