FAMILY AGARICACEAE.
Pileus more or less expanded, convex, bell-shaped; stipe central or nearly so; or the point of attachment lateral, when the stipe may be short or the pileus sessile and shelving. Fruiting surface usually on the under side and exposed toward the earth, lamellate, or prominently folded or veined. Lamellæ or gills radiating from the point of attachment of the pileus with the stipe or with the substratum in the sessile forms; lamellæ simple or branched, rarely anastomosing behind, clothed externally on both surfaces with the basidia, each of which bears four spores (rarely two), cystidia often present.
Key to the North American genera.
THE WHITE-SPORED AGARICS.
(Sometimes there is a faint tinge of pink or lilac when the spores are in bulk, but the color is not seen under the microscope.)
| Plants soft, fleshy or nearly so, usually soon decaying; dried plants do not revive well when moistened. | 1 | ||
| Plants tough, either fleshy or gelatinous, membranaceous, corky or woody, persistent, reviving when moistened. | 13 | ||
| 1— | Gills acute on the edge. | 2 | |
| Edge of the gills obtuse, or gills fold-like, or vein-like, but prominent. | 12 | ||
| 2— | Trama of the pileus of interwoven threads, not vesiculose. | 3 | |
| Trama of the pileus vesiculose, plants rigid but quite fragile. | 11 | ||
| 3— | Gills thin, not much broadened toward the pileus. | 4 | |
| Gills broadened toward the pileus, of waxy consistency. | Hygrophorus. | [110] | |
| 4— | Stipe central or sub-central. (Some species of Pleurotus are sub-central, but the gills are usually not decurrent.) | 5 | |
| Stipe on one side of the pileus, or none, rarely with the stipe sub-central. (Some species of Clitocybe are sub-central.) | Pleurotus. | [102] | |
| 5— | Stipe fleshy, pileus easily separating from the stipe, gills usually free. | 6 | |
| Stipe fleshy or fibrous and elastic, pileus confluent with the stipe and of the same texture. | 7 | ||
| Stipe cartilaginous, pileus confluent with the stipe, but of a different texture. | 9 | ||
| 6— | Volva and annulus present on the stipe. | Amanita. | [52] |
| Volva present, annulus wanting. | Amanitopsis. | [74] | |
| Volva wanting, annulus present. | Lepiota. | [77] | |
| 7— | Annulus and volva wanting. | 8 | |
| Annulus usually present (sometimes vague), volva wanting, gills attached to the stipe. | Armillaria. | [83] | |
| 8— | Gills sinuate. | Tricholoma. | [87] |
| Gills decurrent, not sinuate. | Clitocybe. | [89] | |
| 9— | Gills decurrent, pileus umbilicate. | Omphalia. | [100] |
| Gills not decurrent. | 10 | ||
| 10— | Margin of pileus at first involute, pileus flat or nearly so, somewhat fleshy (some plants rather tough and tending toward the consistency of Marasmius). | Collybia. | [92] |
| Margin of the pileus at first straight, pileus slightly bell-shaped, thin. | Mycena. | [93] | |
| Gills usually free, pileus deeply plicate so that the gills are split where they are attached to the pileus, pileus membranaceous, very tender but not diffluent. | Hiatula. | ||
| 11— | Plants where bruised exuding a milky or colored juice. | Lactarius. | [114] |
| Plants not exuding a juice where bruised. | Russula. | [125] | |
| 12— | Gills decurrent, dichotomous, edge blunt. | Cantharellus. | [128] |
| Gills not decurrent, plants parasitic on other mushrooms. | Nyctalis. | ||
| 13— | Edge of gills not split into two laminæ. | 14 | |
| Edge of gills split into two laminæ and revolute. | Schizophyllum. | [136] | |
| 14— | Plants leathery, either fleshy, membraneous, or gelatinous. | 15 | |
| Plants corky or woody (placed by some in Polyporaceæ). | Lenzites. | ||
| 15— | Stipe separate from the pileus (hymenophore), easily separating. | 16 | |
| Stipe continuous with hymenophore. | 17 | ||
| 16— | Plants tough and fleshy, membranaceous or leathery. | Marasmius. | [130] |
| Plants gelatinous and leathery. | Heliomyces. | ||
| 17— | Edge of the gills acute. | 18 | |
| Edge of the gills obtuse. | 19 | ||
| 18— | Edge of gills usually serrate. | Lentinus. | [134] |
| Edge of gills entire. | Panus. | [134] | |
| 19— | Gills dichotomous. | Xerotus. | |
| Gills fold-like, irregular. | Trogia. | [137] |
There are only a few rare species of Hiatula, Nyctalis, Heliomyces and Xerotus in the United States. None are here described.
THE OCHRE-SPORED AGARICS.
(The spores are yellowish brown or rusty brown.)
| Gills not separating readily from | 1 | ||
| Gills sometimes separating readily from the pileus, forked or anastomosing at the base, or connected with vein-like reticulations. | Paxillus. | [165] | |
| 1— | Universal veil not arachnoid (i. e., not cobwebby). | 2 | |
| Universal veil arachnoid, distinct from the cuticle of the pileus, gills powdery from the spores. | Cortinarius. | [161] | |
| 2— | Stipe central. | 3 | |
| Stipe eccentric or none. | Crepidotus. | [159] | |
| 3— | Volva or annulus present on stipe. | 4 | |
| Volva and annulus wanting. | 5 | ||
| 4— | Stipe with an annulus. | Pholiota. | [150] |
| Stipe with a volva. Locellina (not reported in U. S.). | |||
| 5— | Gills free from the stem. | Pluteolus. | |
| Gills attached. | 6 | ||
| 6— | Gills not dissolving nor becoming powdery. | 7 | |
| Gills dissolving into a gelatinous or powdery condition, not diffluent as in Coprinus. | Bolbitius. | [163] | |
| 7— | Stipe fleshy. | 8 | |
| Stipe cartilaginous or sub-cartilaginous. | 10 | ||
| 8— | Gills somewhat sinuate. | 9 | |
| Gills adnate or decurrent. | Flammula. | [156] | |
| 9— | Cuticle of the pileus silky or bearing fibrils. | Inocybe. | [158] |
| Cuticle of pileus smooth, viscid. | Hebeloma. | [157] | |
| 10— | Gills decurrent. | Tubaria. | [159] |
| Gills not decurrent. | 11 | ||
| 11— | Margin of pileus inflexed. | Naucoria. | [153] |
| Margin of pileus straight, from the first. | Galera. | [155] |