Source: Index Fungorum
[Bjerkandera biformis (Fr.) P. Karst., more]
Trichaptum biforme (Fr.) Ryvarden
Norw. J. Bot. 19 (1972) 237; Ryvarden and Johansen, Prel. Polyp. Fl. E. Africa (1980) 593.
Polyporus biformis Fr. (1833); P. friesii K1. (1833); P. pergamenus Fr. (1838); P. elongatus Berk. (1842); P. xalapensis Berk. et Curt. (1849); P. laceratus Berk. (1839).
Coriolus biformis (Fr.) Ames (1913); Trametes biformis (Fr.) Pilát (1939); Microporellus friesii (KI.) Ryv. (1972); Hirschioporus friesii (KI.) Reid (1975).
Pileus -6 cm in radius, spathulate to flabelliform, sometimes divided into cuneate segments, slightly ascending, thin, flat, rather rigid, often densely imbricate, sessile, to substipitate, inoderm and nearly smooth distally, scabrous villous towards the base, pallid straw yellow to pallid fawn ochraceous, often tinged flesh colour, with faint or brownish zones, usually purplish lilaceous towards the growing margin and often pinkish zoned, drying incurved; margin thin, subacute, becoming deeply lobed and incised; arising from a thin whitish or cream-coloured mycelial pad, often as a discoid base to isolated substipitate pilei, sometimes spreading as a thin felt up to 30 cm long and developing numerous pilei. Tubes -1.5(-2) mm long, whitish to yellowish; pores 70-120 µm wide, dissepiments 40-100 µm thick, becoming 100-200 µm wide with toothed to subirpicoid dissepiments, often 2-3 confluent, even subgyrose, but persistently entire in some collections, white to pale cream, drying pale ochraceous. Flesh 0.52 mm thick at the base of the pileus, thin, fibrous, subcoriaceous, white, no crust. Smell often rather strong as in Ganoderma.
On dead fallen stick, branches and trunks in lowland and montane forest. Cosmopolitan, tropical and temperate; Malaya to the Solomon Islands, rather common.
Spores 4-5 x 2-2.5 µm or 4.5-5.2 x 2.5-3 µm, white in the mass, smooth, ellipsoid, aguttate, not dextrinoid; 5-6.5 x 2-2.5 µm (Ryvarden), 4-6 x 1.5-2 µm (Cunningham), 6-8 x 2-2.5 µm (Overholts). Basidia 15-22 x 4-6 µm, 4-spored. Cystidia 10-32 x 3-6 µm, subcylindric, subclavate or subventricose, walls firm to slightly thickened and colourless, the obtuse apex with a cap of minute crystals partly soluble in potash, shortly projecting, hymenial and as cystidiiform ends of skeletal hyphae. Gloeocystidia and hyphal pegs non. Hyphae more or less dimitic (dl to d3) or subtrimitic in the flesh, not encrusted, not agglutinated, not dextrinoid, the tissue easily teased apart, in the flesh often somewhat microfibrillar; generative hyphae 1.5-4 µm wide, clamped, walls thin or -1 µm thick, cells -200 µm long, in places rather intricately branched and appearing as binding hyphae (but with clamps); skeletal hyphae 4-6 µm wide, -8 µm in potash, the lumen becoming more or less obliterated, aseptate, unbranched and apparently unlimited, or as intercalary cells -800 µm long with 1(-2) subterminal branches, mediate hyphae 2.5-3.5 µm wide; binding hyphae (when present) 2-4 µm wide, often laxly branched; dissepiments fully dimitic (d3) with longitudinal, easily separable, skeletal hyphae 2.5-4 µm wide (3-6 µm in potash), not agglutinated, without gloeocystidial ends. Surface of pileus in the distal part with more or less appressed skeletal hypha ends, some projecting -50(-100) µm; in the proximal part with a villous layer 300-500 µm thick, composed of generative and skeletal hyphae (sometimes fasciculate).