Inocybe lineata E. Horak, Matheny & Desjardin, 2015

Horak, Egon, Matheny, P. Brandon, Desjardin, Dennis E. & Soytong, K., 2015, The genus Inocybe (Inocybaceae, Agaricales, Basidiomycota) in Thailand and Malaysia, Phytotaxa 230 (3), pp. 201-238 : 230-232

19. Inocybe lineata E. Horak, Matheny & Desjardin , spec. nov. Fig. 18a–h ; Pl. 6a–b

MycoBank 519915

Etymology: lineatus (Lat.), striate, streaked.

Diagnosis: Similar to Inocybe parvibulbosa but I. lineata differs by the larger basidiomes (pileus 18–26 mm wide, stipe 25–50 × 2–3 mm), narrower basidiospores, and the non-gelatinized trichoderm or cutis-like pileipellis. Pileus center scurfy or with small scales, margin conspicuously splitting and sulcate-plicate. Stipe entirely pruinose, with a distinct marginate bulb, cortina absent. Basidiospores 8.5–10 × 6–7.5 μm, distinctly nodulose, with hemispherical or broadly conical projections. Cheilocystidia, pleurocystidia, and caulocystidia 45–60 × 15–20 μm, broadly fusoid or lageniform, with hyaline walls up to 3.5 μm thick at the apex. In tropical montane forest dominated by Dipterocarpus , Castanopsis , Thailand.

Holotype:— THAILAND. Chiang Mai Prov.: Hwy 1095, at 22 km marker, N19˚07‘570‘‘, E98˚45 ‘647‘‘, on soil in tropical montane forest (dominated by Dipterocarpus ), 4 Jun. 2006, leg. T.J. Baroni & D. E. Desjardin ( DED8019 , holotype, SFSU; ZT13019 , isotype) GenBank accession no. EU569861.

Pileus 18–26 mm wide, at first conical, campanulate or umbonate expanded in age; surface dry, veil remnants absent, with small, scurfy also recurved squamules at disk (and between radial streaks), fibrillose towards conspicuously splitting and sulcate-plicate margin; dark brown (7F5–7) or fuscous, pale olive brown (7E4–5) towards the margin, exposed subpellis greyish yellow (4B3). Lamellae 36–42 reaching stipe, (3–) 7 lamellulae, close, ascending or adnexed, up to 4 mm wide, brown (6–7E4); edges entire or subfimbriate, concolorous or whitish. Stipe 25–50 × 2–3 mm, central, cylindrical, equal but with distinctive cup-shaped marginate bulb, up to 6 mm wide; surface pruinose all over, dry, pale brown or greyish brown or brownish orange (6B3) over whole length, occasionally with faint incarnate tint, edge of basal bulb white; cortina absent; context solid, white, weakly incarnate upon exposure. Odor not distinctive or faintly sour. Taste not recorded.

Basidiospores 8.5–10 × 6–7.5 μm, ellipsoid, distinctly nodulose, hemispherical or broadly conical projections up to 3 mm high, yellow-brown, brown in deposist. Basidia 20–28 × 8–10 μm, 4-spored, clavate. Cheilocystidia 45–60 × 15–20 μm, broadly fusoid or lageniform, metuloid, with hyaline walls up to 3.5 μm thick at apex, crystals present; paracystidia 15–20 × 8–9 μm, clavate, hyaline, thin-walled. Pleurocystidia similar to cheilocystidia. Caulocystidia similar to cheilocystidia, intermixed with clavate, hyaline, thin-walled cells. Pileipellis a trichoderm or cutis of erect or repent, cylindrical hyphae, 3–4 μm wide, terminal cells not differentiated, non-gelatinized wall encrusted with (yellow-) brown pigment; subpellis composed of short cylindrical hyphae 8–15 μm wide, walls hyaline, encrusted with yellow-brown pigment; oleiferous hyphae absent. Clamp connections present.

Habitat: On soil in tropical montane forest (dominated by Dipterocarpus , Castanopsis ), 1050–1150 m elev.

Known distribution: Northwest Thailand.

Other specimens examined: THAILAND. Chiang Mai Prov.: Hwy 1095, near 27 km marker, N19˚06‘28.8‘‘, E98˚44 ‘47.3‘‘, 1050 m elev., on soil in tropical montane forest (dominated by Castanopsis ), 8 Jun. 2006, leg. T.J. Baroni & D. E. Desjardin ( DED8048 , SFSU; ZT13020 ) GenBank accession no. GQ892958 .

Notes: In the field the brown or fuscous colored basidiomes of I. lineata resemble those of the closely related I. parvibulbosa , although the basidiomes of I. lineata are larger. The two sympatric Thai species are distinguished by the size of the basidiomes and the surface structure of the pileipellis. Morphotaxonomically, the two species share similar basidiospores and distinctly metuloid cystidia.

Figures

PLATE 6. a. Inocybe lineata (DED8019, holotype). b. Inocybe lineata (DED8048). Scale bars = 10 mm. Photos by Dennis Desjardin.

FIGURE 18. Macroscopic and anatomical features for Inocybe lineata (DED8019, holotype). a. Basidiomes. b. Basidiospores. c. Basidia. d. Cheilocystidia. e. Paracystidia. f. Pleurocystidia. g. Pileipellis. Scale bars: basidiomes = 20 mm, basidiospores = 10 μm, basidia and cystidia = 20 μm, pileipellis = 40 μm. Drawings by Egon Horak.