Psathyrella lacuum Huijsman

Diagnosis Fuente: PERSOONIA - Suplement - Vol. 2 - THE DUTCH, FRENCH AND BRITISH SPECIES OF PSATHYRELLA - 1985 E. KITS VAN WAVEREN - Rijksherbarium, Leiden, The Nederlands
     Cap 4—-10(—20) mm broad, plano-convex to applanate, pale pink to pinkish lac trom lamellae shining through, translucently striate up to disc, hygrophanous, drying out to white, cream to sordid yellow at centre, with crenulate edge. Veil on cap as scattered, white, arachnoid fibrils, sometimes also persisting on stem. Gills rather narrow, adnate, subventricose, crowded, at first white, later pale greyish lilac with pale edge. Stem 10—15 x 0.7—1.5 mm, cylindrical, slightly thicker at base, curved, hollow, hyaline-white, white-flocculose sub lens. Trama of ‘washed’ gill in NH,OH 10% under binocular lens yellowish (Mu. 10 YR 6/6—6/4) from base to edge. Spore print purplish brown.
     Spores 6.3-8 x 4—5(—5.5) um (mean values 7—7.2 x 4.5—4.7 pm: 2 collections), ellipsoid, adaxially flattened, in water, NH,OH 10%, and KOH 5% yellowish brown (Mu. + 10 YR5/4), not opaque, with distinct germ pore (1.8 ym), with very small hilar appendix. Basidia11-14.5 x 6,5—8 pm, clavate, 4-spored. Pleurocystidia absent. Marginal cells: spheropedunculate and clavate cells 17.5-25 x 10—15 um, numerous; utriform cystidia very rare and of same size; all cells thin-walled, colourless. Hymenophoral trama in NH,OH 10% sub micr. pale to very pale brownish yellow from membranal pigment, without yellow hyphal septa or encrustations.
HABITAT & DISTRIBUTION, — Subcaespitose on wood partly immersed (wooden-handle of brush standing in water-filled pot). Known only from type locality.