Psilocybe guilartensis

Psilocybe guilartensis Guzmán, Tapia & Nieves-Rivera (1997)


Description: Psilocybe guilartensis is a psilocybin mushroom which has psilocybin and psilocin as main active compounds. It is common in Puerto Rico. First reported in the literature in 1997, Gastón Guzmán placed Psilocybe guilartensis in Psilocybe section Brunneocystidiatae due to its blue staining reaction, small thick-walled subrhomboid spores, and pigmented cystidia. Other mushrooms in the section Brunneocystidiatae include Psilocybe banderillensis, Psilocybe banderillensis var. paulensis, Psilocybe brunneocystidia, Psilocybe heimii, Psilocybe inconspicua, Psilocybe pleurocystidiosa, Psilocybe rzedowski, Psilocybe singerii, Psilocybe uxpanapensis, Psilocybe veraecrucis and Psilocybe weldenii.

Macroscopic feat.:
  • Cap/Pileus: 1-3 cm in diameter, initially subconical to campanulate (bell-shaped), expanding to plano-convex with an umbo. Cap surface dark violet brown in color, translucent-striate near the margin, hygrophanous, fading to tan as it dries. Staining blue-green to black where bruised.
  • Gills/Lamellae: Cream color when young, violet brown or chocolate brown in age, with adnexed attachment.
  • Stem/Stipe: 3-8 cm long, 1-2 mm thick, central, equal with subbulbous base, hollow and cylindric, color whitish to brown, ornamented with small flattened scales towards the base. The base is covered in tiny yellow fibers which help distinguish this from similar species. Staining blue-green to black where bruised.
  • Odor: And taste farinaceous, sometimes with a slight mustard taste.

Microscopic feat.:
  • Basidio/Spores: Dark violet brown, subrhomboid in face view, subellipsoid in side view, thick walled, 6 x 5 µm.
  • Basidia: Basidia four-spored. Clamp connections common.
  • Pleurocistidia: Present.
  • Cheilocystidia: Pigmented.

Habitat: Psilocybe guilartensis is found growing gregariously, often on disturbed bare clay or moss. Found along hiking trails, in coffee plantations, tropical and subtropical forests, especially in landslide areas. Known only from Puerto Rico and Dominican Republic.

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Description: An emendation of Psilocybe guilartensis, sis presented because morphological features that were not presented in the original protolog of this species (Guzmán et al 1997) have been discovered. Additional taxonomic features include a setaceous and tomentose, mustard-yellow surface coating on the lower part of the stipe, presence of two types of pleuro- and cheilocystidia, cheilocystidia with irregular encrustations at the base, and an occasional odor of mustard.

Macroscopic feat.:
  • Cap/Pileus: (5-) 15-20 (-30) mm diam, conic to campanulate, subumbonate or papillate, becoming plano-convex, umbonate or papillate, smooth or subrimose, moist, violet brown (11F4-6) to dark chocolate brown (6F4), hygrophanous, drying at times to Tawny brown, margin translucent-striate and/or sulcate-striate.
  • Gills/Lamellae: Adnexed, whitish to smoke gray (3C2) at first, finally fuscous, dark purplish (14F4-6) or chocolate brown (6F4), edges concolorous, even to subfimbriate.
  • Stem/Stipe: (22-) 35-60 (-80) x 1-1.5 (-2) mm broad, hollow, white or straw colored at first or concolorous with pileus above; equal with a subbulbous base, inserted to one-third or one-half length, smooth or irregular, appressed squamulose toward the base; base with a tomentose mustard-yellow coating.
  • Context: Context whitish in the pileus, becoming brownish in the stipe. All parts caerulescent when cut or bruised, staining blue-green to blackish.
  • Odor: And taste farinaceous or of mustard, although sometimes very slightly so.

Microscopic feat.:
  • Basidio/Spores: (5-) 5.5-6.5 (-7.5) x (4.5) 5-5.5 (-7) x 4-5 µm (Q = 1.11), subrhomboid or subglobose in face view, subellipsoid in side view, thick-walled, up to 1 µm thick, brownish-yellow, with a conspicuous pore, 0.8-1 µm wide. Spore print Dark Violaceous Brown.
  • Basidia: 20-32 x (4-) 5-7 µm, 4 sterigmate, hyaline, ventricose or subcylindric, with a median constriction.
  • Pleurocistidia: Of two types, type "A" (9-) 13-20 (-28) x 3-5 (-9) µm, common but difficult to find, hyaline, ventricose, submucronate or sublageniform, with a regular or irregular short or long neck; type "B" (12-) 16-28 (-40) x (5.5-) 7-10 (-14) µm, common and easily seen, dark brown or grayish opaque, rarely hyaline, ventricose, subfusoid or bowling-pin shaped, with a subglobose head, with or without a neck.
  • Cheilocystidia: Of two types, type "A" (12-) 14-26 (-30) x (4-) 6-8 (-12) µm, common but difficult to find, hyaline, yellowish or grayish opaque, smooth or with irregular encrusted walls toward the base, lageniform, ventricose-rostrate, or occasionally with swollen base and bifurcate branched rostrate apices; type "B" (12-) 18-28 (-34) x (5-) 6-9 (-12) µm, common and easily seen, colors and shapes similar to pleurocystidia type "B".
  • Subhymenium: Poorly developed, subcellular, hyaline or brownish, with elements 3-10 µm.
  • Trama: Regular, with hyaline to yellowish or brownish cylindrical or inflated hyphae 2,5-8 µm wide or 8-30 µm, wide, both thick-walled, up to 2 µm thick, with brown encrustations.
  • Epicutis: A thin layer of subgelatinized, repent, hyaline or brownish cylindrical hyphae, 1.5-2 µm, wide, rarely with hyaline cylindrical or subclavate pileocystidia, these erect, single or in scattered clusters.
  • Hypodermium: With hyaline to pale yellowish cylindrical or inflated hyphae 3-9 µm, wide, thin-walled, frequently encrusted with brown pigment. Context in pileus and stipe with both hyaline, cylindrical hyphae, 2-4 µm diam, and buff-yellow or brownish, globose elements, which are up to 27 µm. Basal mycelioid covering formed of branching setaceous cylindrical hyphae, up to 70 µm long and 1-4 (-5) µm, thick-walled, walls up to 1,5 µm thick, dark yellow brown, arising from hyaline cylindrical clamped hyphae, that are thin- or thick-walled and 1,5-4 (-5) µm. Clamp connections common.

Habitat: Gregarious on bare clay, covered with mosses, mainly on landslide slopes, in tropical and subtropical forests, known only in Puerto Rico and Dominican Republic.

Studied material: PUERTO RICO, Mun. Adjuntas, Guilarte State Forest, trail to Monte Guilarte Peak, Sep 1994, Nieves-Rivera, Santos-Flores & Betancourt, ledger Nieves Rivera PR-1 (holotype Mapr; isotype Xal). Mun. Villalba, Toro Negro State Forest, trail to Tower 3, Oct 1994, Nieves-Rivera, Santos-Flores & Betancourt (MAPR; NY as Psilocybe plutonia). Mun. Río Grande, Mountains Luquillo, El Verde Research Area, 18 Sep 1999, Rosa & Prieto (PR-3539); Carrasquillo (PR-3537); 19 Feb 1998, Laboy (PR-4862). Caribbean National Forest, Sabana, 3 Jun 1998, Baroni 8744 (CORT); El Yunque, Caimitillo Trail, 29 Jun 1991, Baroni 7983 (CORT); El Verde, 19 Jun 1996, Baroni 7900 (CORT). La Mina Research Area, La Coca Trail, 25 Jun 1997, Llorens, Bonilla & Cantrell (PR-4834); 23 May 2000, Cantrell & Salgado, ledger Cantrell PR-0019 (PR-6166); 26 Nov 1999, Salgado & Argüello-López (PR-5922). Caimitillo Trail, 6 Jun 1997, Llorens (PR-4325); Nieves-Rivera, Llorens & Serrano (PR-4392); 19 Jun 1997, Nieves-Rivera, Llorens & Serrano (PR-4392); 19 Jun 1997, Nieves-Rivera, Llorens & Serrano (PR-4393); Nieves-Rivera, Llorens, Serrano & Bonilla, ledger Nieves-Rivera PR-791 (PR-4394); 11 Jul 1997, Baroni, ledger Nieves-Rivera 796 (PR-4400). Mount Britton Trail, 15 Jul 1997, Llorens & Rodríuez (PR-4835). El Toro Trail, 2 Jul 1997, Cantrell, Nieves-Rivera, Serrano & Llorens (PR-4840). Mun. Luquillo, Luquillo Mountains, Bisley Watersheads, trail to tower, 6 Jun 1997, Lodge (PR-4399); 26 Jun 1997, Llorens (PR-4841). Palo Hueco, El Cacique Area, 10 Jul 1998, Cantrell, Laboy & Negrón, ledger Cantrell PR-9869 (PR-4882); 2 Jul 1999, Cantrell & Laboy (PR-5680). DOMINICAN REPUBLIC, Prov. Santiago, Los Montones Convention Center, altitude 800 m, 27 Nov 1999, Baroni 9028 (DR-1064).

Discussion: The discovery that all collections of Psilocybe guilartensis s have setaceous hyphae at the base of the stipe is a significant addition to the circumscription of this taxon and provides a very helpful character in distinguishing this species. The distinctive pleuro- and cheilocystidia also are important characters that help to define Psilocybe guilartensis. Psilocybe guilartensis is the most common species of Psilocybe collected in Puerto Rico, as evidenced by the numerous collections documenting its abundance. It tends to fruit on bare clay along hiking trails where disturbance has occurred. Its relative abundance might be the result of being collected in readily accessible areas.
The record from the Dominican Republic is the first report of this species from the island of Hispaniola, although this collection (Baroni 9028) lacks the yellowish or grayish opaque pleurocystidia and the brownish or grayish opaque cheilocystidia that are typical of Psilocybe guilartensis. However, the presence of the highly distinctive setaceous hyphae at the base of the stipe indicates this collection has strong phenotypic affinities with Psilocybe guilartensis. The lack of pigments in the hymenial cystidia might be due to the immaturity of the specimens that make up this collection. For now, based on macromorphology, basidiospore morphology and setaceous hyphae at the base of the stipe, we consider this collection as conspecific with Psilocybe guilartensis.
As pointed out by Guzmána et al (1997) Psilocybe guilartensis belongs in section Brunneocystidiatae because of the pigmented hymenial cystidia, thick-walled rhomboid or subrhomboid basidiospores that are less than 8 µm long and bluing of the basidiomata when injured. The setaceous hyphae at the base of the stipe, the two distinct types of pleuro- and cheilocystidia, especially the hyaline inflated cheilocystidia with encrusted bases and bifurcate branched apices, are features that clearly separate Psilocybe guilartensis from the similar Psilocybe pleurocystidiosa (Guzmán 1983).

source - [95 (6): 1178-1179]

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