Laxitextum bicolor (Pers.) Lentz., U.S. Dept. Agric. Monogr.

Henkel, Terry W. & Ryvarden, Leif, 2021, A SYNOPSIS OF THE WOOD-DECAY GENUS LAXITEXTUM (HERICIACEAE, RUSSULALES, BASIDIOMYCOTA) AND A NEW SPECIES FROM CAMEROON, Edinburgh Journal of Botany 78 (348), pp. 1-9 : 2-4

1. Laxitextum bicolor (Pers.) Lentz., U.S. Dept. Agric. Monogr. 24: 19 (1956 [1955]). Figure 1 . Thelephora bicolor Pers., Syn. Meth. Fung. 2: 568 (1801); Mycol. Eur. I: 122 (1822), nom. sanct. (Fr., Syst. Mycol. I: 438 [1821]).

Basidiomata resupinate or subpileate, upper side brown, in young specimens finely tomentose, in old specimens with more adpressed hairs, often indistinctly zonate and radially striate; hymenium in young fresh basidiomata pure white, darkening slightly to cream, then pale brownish, glabrous, cracking when dried, in section about 1 mm thick, the upper part of the trama (i.e. the subiculum of resupinate specimens), brown, the subhymenial part whitish; margin white and finely fibrillose in young specimens.

Hyphal system monomitic; hyphae of the brown trama distinct, with thin or somewhat thickened walls, light brown in the microscope, usually 2.5–4 μm wide; subhymenial hyphae thin-walled, in old basidiomata partly collapsed and forming a hyphal net with irregular meshes, penetrated by very thin-walled, cytoplasm-filled generative hyphae, these 1–3 μm wide.

Gloeocystidia present, in the young state fusiform, subulate, often with a moniliform apical appendix, more or less projecting, in old specimens tube-like, mostly obtuse, of highly varying length, 40–100 μm or longer, 5–10 μm wide, consistently filled with a yellowish oily substance.

Basidia narrowly clavate, 20–30 × 3.5–5 μm, tetrasterigmate.

Basidiospores oblong-ellipsoid, thin-walled, finely echinulate, 4.5–5 × 2.5 μm, amyloid.

Substratum. On decayed hardwoods.

Distribution. Cosmopolitan to 70°N in Norway.

Laxitextum bicolor is rather easy to recognise because of the contrasting brown upper and white lower colours and soft consistency.

Figures

Figure 1. Microscopic features of Laxitextum bicolor. A, Section through the basidioma; B, tramal hyphae; C, subhymenium, cystidia, basidioles and basidia; D, basidiospores; E, mature basidium; F, young cystidia; G, older cystidium. Drawn from Eriksson 9318 (O) by J. Eriksson.