Name: Psilocybe subaeruginascens
Citation: Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 123: 78 (1914)
Deprecated Synonyms: Psilocybe subaeriginascens
Misspellings: Psilocybe subaeruginacens
Pileus 20 – 30 mm diam., broadly and obtusely campanulate, ivory or pale grey-argillaceous, at disc with blue-green tinge, smooth, dry, veil remnants absent. – Lamellae 16-24 reaching stipe, lamellulae in 5 – 7 series, broadly adnate, at first pale brown, becoming fuscous in old specimens, fimbriate edges whitish.-Stipe 4 0 – 6 5 × 2 – 3 mm. cylindrical, equal, white, turning blue-green upon handling, dry, hollow, rather tough, smooth to slightly fibrillose, base with conspicuous white rhizoids and mycelial strands attached to substrate, solitary. – Ring fragile and non- persisting, membranaceous, non-striate, hanging, white. Context rather tough, white, blueing upon exposure. Odor unpleasant, fetid. Taste unknown. Chemical reactions on pileus: KOH-negative.
Spore print dark fuscous or black.
Basidiospores 8-9.5x 5 – 6.5 × 4.5 – 5.5 um, elliptical to subrhomboid in face view, amygdaliform in side view, thick-walled (1-1.3 um diam.), with distinctive apical germ pore, smooth, opaque. Basidia 24- 3 0 × 6 – 8 urn, cylindrical or constricted-suburniform, 4-spored, sterigmata up to 7 urn long. Cheilocystidia 18 – 24 × 6 – 10 um, polymorphic, shape ranging from fusoid to subutriform, thin- walled, hyaline, apex rounded or subcapitate, occasionally covered with thin, hyaline incrustation (also in KOH!). – Pleurocystidia and caulocystidia absent. – Pileipellis a thin cutis composed of cylindrical, repent, hyaline to pale yellow, non-gelatinized, non- incrusted hyphae, 4-10 urn diam., distinctive terminal cells absent. Subpellis composed of irregularely interwoven, cylindrical or puzzle-like, hyaline, thin-walled hyphae. Clamp connections present.
Etymology: subaeruginascens (Lat.) – similar to “aeru- ginascens”.
Specimens examined: INDONESIA: Java: Bogor (Buitenzorg), 1907, leg. Höhnel 3942 A (holotype, FH); Bogor, Botanical Garden, on soil among rotting litter of broadleaf trees, 20 Jan 1999, leg. Horak ZT 7229 (BO 99 – 355).
Habitat and Ecology: Coprophilous or saprobic. – On horse manure (type) or on soil among litter, in tropical-lowland broadleaf forest.
Distribution: Indonesia: Java.
Discussion: Owing to the blueing basidiomes Ps. subaeruginascens is considered to be psychoactive.
The type specimen consists of two fragmented basidiomes, plus broken fragments of stipe and lamellae. There is one intact, pale tawny brown pileus, 12 mm diam. No partial veil remnants recognizable on the stipe fragments.
The topotypical material mentioned above (BO 99-355) corresponds in all essential characters with the type specimens gathered nearly 100 years ago by F.v. Höhnel. Macroscopically, the most distinctive features are its habit and the blue-green colors on ageing and handled specimens. In the field this Psilocybe can readily be mistaken for a taxon of Copelandia, a widely distributed genus in tropical-subtropical habitats in SE-Asia (Horak 1980, Gerhardt 1996). Microscopically, however, Ps. subaeruginascens is clearly separated by its non-metuloid cystidia and the lack of green-blue crystals or incrustation (in KOH) at the apex of the cystidia.
Based upon the re-examination of the type specimen, Guzman (1983) and Thomas & al. (2002) emphasize that Psilocybe subaeru- ginascens and Ps. aerugineomaculans are actually contaxic. It is noteworthy, however, that Guzman (1995) has abandoned this concept and subsequently accepted two independent taxa.
Our observations also demonstrate that morphologically these two taxa are distinctly separated (cf. enclosed key). In addition, Guzman (1983) refers to a Japanese collection which purportedly represents the first Japanese record of Ps. subaeruginascens. The drawings of the basidiomes definitely do not relate to the original descriptions of the two before-mentioned Javanese taxa. In the meantime, Guzman (1995) accomodated the Japanese specimens in the new taxon Ps. septentrionalis.
The fresh topotypical material of Ps. subaeruginascens allows for the first time to present its distinctive, microscopical characters. Under these circumstances the identity and concepts of several blueing species recorded from Australia (Margot & Watling 1981; Chang & Mills 1992, Grgurinovic 1997) and New Zealand (Guzman, Bandala & King 1991, 1993; Johnston & Buchanan 1995) are in need of critical re-evaluation.
It is remarkable that Bogor (Buitenzorg) is also the type locality of the second Javanese species with blueing and macroscopic-ally similar basidiomes viz. Ps. aerugineomaculans (see below). As already pointed out by Höhnel in the relevant protologues, these two taxa are readily distinguished by the colors of the basidiomes and the shape of the basidiospores.