Pileus 10-15 mm broad, 8-10 mm high, convex, hygrophanous, dingy or sordid yellowish brown (5E5), darker (6E5) at disc, fading to greyish yellow (close to 4B4). Lamellae adnate to subdecurrent, subdistant, greyish brown (6E4). Stipe 48-60 mm long, 1-2 mm thick, hollow, flexuose, tapering towards the base, translucent orange-brown becoming browner at the base. Context thin, concolorous with the pileus.
Spores 9.6-11.7 × 5.8- 7.1 × 5.6-7.1 um, subellipsoidal in face view, slightly inequilateral in profile, germ pore minute but distinct. Basidia 23.7-32.5 (-35.8) x 6 . 7 – 10.8 um, the majority 4-spored, more rarely 2- spored. Pleurocystidia as chrysocystidia, 45-77.5 × 10.8-17.5 urn, ventricose, the apical and/or basal portions elongate clavate and prominent. Cheilocystidia 26.7-44.8 × 6.1-9.2 um, thin-walled, hyaline, clavate, sessile or pedicellate lageniform, intermixed with chrysocystidia. Subhymenium subcellular. Trama regular. Epicutis a layer of repent, encrusted, brown hyphae, clamp connections present. Hypodermium subcellular, with broad, short, clamped hyphae.
Solitary amongst Sphagnum and Polytrichum in wet and boggy areas.
Holoype: Tasmania, Arve Road, near Geeveston, 15 May 1991, Y.S. Chang, CYS543 (HO306006).
Other specimens examined: Tasmania, Arve Road, near Geeveston, solitary amongst Sphagnum, 6 May 1991, A.K. Mills, CYS531 (HO306007); Mt Read, on muddy or boggy embankment, scattered, April 1991, A.K. Mills, AKM1001.
Comments: Psilocybe paludicola sp. nov. is not typically gregarious and carpophores are either solitary or widely scattered. The habit and habitat suggest that the species belongs in section Psilocyboides (Sing.) Noordel., subsection Elongatae Noordel. The new species differs from Psilocybe polytrichi (Fr. : Fr.) Pears. & Dennis, a widespread species found in the boreal and temperate regions of Europe and North America, in having longer and broader spores. However, the spore size and all characters of the pileus, stipe and lamellae of P. paludicola closely match those of Psilocybe elongata (Pers. : Fr.) J. Lange, a widespread and common species of the Northern Hemisphere, found in moors and peat bogs, preferring Sphagnum but also occurring amongst other mosses and sometimes on bare peat. The possibility that it is part of the P. elongata species complex recognised by Noordeloos (1999), …