Division I
Key to Hymenomycetes, Membrane Fungi
Hymenomycetes or membrane fungi are divided into two sections:
Section A, with cap.
Section B, without cap.
Section A is divided into four classes:
I. Mushrooms with radiating gills beneath caps, gill-bearing mushrooms (Agarics).
II. With pores or tubes beneath caps (Polyporei).
III. With spines or teeth beneath the cap or branches (Hydnei).
IV. Where the spore-bearing surface beneath the cap is even, smooth, or slightly wrinkled (Thelephorei).
Section B is divided into two classes:
I. Plants club-shaped and simple, or bush-like and branched (Clavariei).
II. Plants gelatinous and irregular (Tremellinei).