Key to Crust and Parchment Fungi (no pores, teeth, or gills)

1. Fruit body occurring as 1) projecting shelf-like or petal-like caps (parchment-like in texture) with or without
    resupinate (crust-like) portions or 2) flattened cup-like or disc-shaped structures, circular to irregular in outline
    with margins free and elevated from the substrate

    2. Fruit body a flattened cup-like or disc-shaped structure, circular to irregular in outline with margins free and
        elevated from the substrate; fruit bodies may be confluent ....................Aleurodiscus wakefieldiae

    2. Fruit body occurring as projecting shelf-like or petal-like caps (parchment-like in texture) with or without
        resupinate (crust-like) portions

        3. Fertile resupinate surface brown with conical setae (use hand lens), surface smooth or cracked; caps
            brownish and concentrically zoned; flesh turns blackish with KOH; fruit bodies often fuse laterally to form
            larger colonies...............................................................................Hymenochaete tabacina complex

        3. Fertile surface without conical setae; flesh not blackish with KOH

            4. Cap pale gray/silvery and covered with tiny radiating silky fibers; caps 0.5-1 cm wide but often laterally
                fused; fertile surface whitish, growing dead twigs and branches of hornbeam
                (Carpinus caroliniana) ....................................................................................... Stereum striatum

            4. Cap typically hairy but color, size, and substrate not as above

                5. Caps 1-7 cm wide; distinctly zoned with shades of dark brown, rust, and gray; fertile surface buff to
                    cinnamon-buff; typically forming individual brackets rather than fusing ....................Stereum ostrea

                5. Caps 0.3-2 cm wide, zonate, often fused laterally

                    6. Cap covered with coarse, stiff hairs; fertile surface buff to gray......................Stereum hirsutum

                    6. Cap silky hairy, smooth and shiny near margin, radially furrowed; fertile surface orange but fading
                        to cinnamon-buff, slightly ridged where caps join .......................................Stereum complicatum

1. Fruit body appearing as 1) a sheetlike or crustlike spreading form or 2) a swollen, blackish spindle-like growth on
    twigs or 3) closely arranged, broken pieces of whitish to grayish to tanish ceramic tile

    7. Fruit body sheetlike, crustlike, spreading in appearance

        8. Fruit body soft, fluffy, slimy, yellowish, spreading mass at first; maturing into dry, ochre to red-brown
            mass up to 20 cm long, 1-3 cm thick; with a brittle crust and blackish, powdery, dry
            spore mass underneath .................................................................................................Fuligo septica

        8. Fruit body hard, blackish, carbon-like

            9. On stumps and roots of decaying hardwoods; surface irregular with bump-like pores giving finely
                roughened appearance; flesh 3-6 mm thick; often brittle and easily detached...............Ustulina deusta

            9. On decaying hardwood branches, often encircling them; surface finely roughened to nearly
                smooth and shiny, sometimes cracked; flesh 1-1.5 mm thick.......................................Diatrype stigma

    7. Fruit body as swollen, blackish spindle-like growths on twigs or as closely arranged, broken pieces of whitish
        to grayish to tanish ceramic tiles

       10. Fruit body as spindle-shaped or as knot-like swellings on cherry (Prunus) twigs and
             branches.............................................................................................................Apiosporina morbosa

       10. Fruit body hard and woody; appearing as closely arranged, small, broken pieces of whitish
             to pinkish-buff tiles typically on debarked oak logs and stumps .............................Xylobolus frustulatus