1. Agaricaceæ. Hymenium with gills.
  2. Polyporaceæ. Hymenium with pores.
  3. Hydnaceæ. Hymenium with spines.
  4. Thelephoraceæ. Hymenium horizontal and mostly on the under surface.
  5. Clavariaceæ. Hymenium on a smooth club-shaped surface.
  6. Tremellaceæ. Hymenium even and superior. Gelatinous fungi.

Family 1—Agaricaceae.

Figure 7.—Spore-print of Agaricus arvensis.

In the Agaricaceæ or common mushrooms, and in all other of similar structure, the spore-producing membranes are found on the under surface of the cap. They consist of thin lamellæ, or gills, attached by the upper edge to the cap and extending from the stem to the margin of the cap. Very frequently that space may be entirely utilized by shorter lamellæ, or gills, intervening between the longer, especially toward the margin of the cap. In a few species where the stem seems to be wanting, or where it is attached to the side of the cap, the lamellæ, or gills, radiate from the point of attachment or from the lateral stem to other parts of the circumference of the cap. Berkeley gives the following characteristics: Hymenium, inferior, spread over easily divisible gills or plates, radiating from a center or stem, which may be either simple or branched.

This family includes the following genera:

  1. Agaricus—Gills, not melting, edge acute; including all the sub-genera which have been elevated to the rank of genera.
  2. Coprinus—Gills deliquescent, spores black.
  3. Cortinarius—Gills persistent, veil spider-web-like, terrestrial.
  4. Paxillus—Gills separating from the hymenophorum and decurrent.
  5. Gomphidius—Gills branched and decurrent, pileus top-shaped.
  6. Bolbitius—Gills becoming moist, spores colored.
  7. Lactarius—Gills milky, terrestrial.
  8. Russula—Gills equal, rigid, and brittle, terrestrial.
  9. Marasmius—Gills thick, tough, hymenium dry.
  10. Hygrophorus—Stem confluent with the hymenophorum; gills sharp edged.
  11. Cantharellus—Gills thick, branched, rounded edge.
  12. Lentinus—Pileus hairy, hard, tough; gills, tough, unequal, toothed; on logs and stumps.
  13. Lenzites—Whole plant corky; gills simple or branched.
  14. Trogia—Gills venose, fold-like, channelled.
  15. Panus—Gills corky, with acute edge.
  16. Nyctalis—Veil universal; gills broad, often parasitic.
  17. Schizophyllum—Gills corky, split longitudinally.
  18. Xerotus—Gills tough, fold-like.

Therefore the gill-bearing fungi are known under the family name, Agaricaceæ, or more generally known as Agarics.