Conocybe maculatostriata H. B. Song & S. M. Tang 2026, sp. nov.
Year: 2026
Type: article
Abstract: Conocybe maculatostriata H. B. Song & S. M. Tang sp. nov. Figs 2 D, 3 B, 3 C, 6, 7 Etymology. The specific epithet “ maculatostriata ” refers to a pileus with maculate stripes when moist. Holotypus. China • Xizang Autonomous Region, Xigazê City, Chomo County, 24 July 2025, 27°37'12"N, 88°56'24"E, alt. 3607 m, S. M. Tang, 2025072431 (FJAU 78852). Diagnosis. The key taxonomic feature of this species is its pileus with maculate stripes when moist and the large capitulum diameter of its lecythiform cystidia; the latter feature overlaps with species of ser. Magnicapitata. However, it can be distinguished from other species in ser. Magnicapitata by its maculate stripes when moist, slightly larger basidiospores (9.7–12.8 μm), and the median constriction observed in some basidia. Description. Basidiomata mycenoid. Pileus 5–15 mm, first nearly hemispherical to obtusely conical, then paraboloid to campanulate, aspects of margin straight, undulate, center clay brown (RAL 8003) to copper brown (RAL 8004), salmon pink (RAL 3022), margin salmon pink (RAL 3022) to beige red (RAL 3012), copper brown (RAL 8004). Hygrophanous, maculate stripes when moist, smooth, glabrous, striate to half the pileus center. Context thin, salmon pink (RAL 3022) to copper brown (RAL 8004), with no specific odor or taste. Lamellae adnexed to narrowly adnate, ventricose to nearly segmentiform, moderately crowded, unequal in length, ochre brown (RAL 8001) to copper brown (RAL 8004), orange brown (RAL 8023), margin even. Stipe 10–25 mm long, 0.5–1 mm thick, cylindrical, salmon pink (RAL 3022) to copper brown (RAL 8004), red brown (RAL 8012), surface pruinose, with longitudinal fibrillose striations, base subbulbous. Basidiospores (60 / 3 / 2) (9.2 –) 9.7–12.8 (– 13.1) × (5.1 –) 5.3–7.2 (– 8) μm, Q = (1.44 –) 1.49–2.03 (– 2.16), Qm = 1.77 (± 0.18), lateral view slightly ellipsoid to oblong, subcylindrical, occasionally frontal view faintly hexagonal, wall slightly thick, containing oil droplets, germ pore diameter 1.5–2.5 μm, basidiospores in KOH solution copper brown (RAL 8004) to pearl orange (RAL 2013). Basidia (16 –) 17–24 (– 27) × 8–12 μm, polymorphic, clavate to cylindrical, some median constriction, utriform, 4 - spored, sterigmata 2–5 μm long, vacuolar contents in basidia. Cheilocystidia (22 –) 23–30 (– 31) × (8 –) 10–15 (– 16) μm, lecythiform (body lageniform, broadly ellipsoid to oblong, some subglobose), capitula 6–9 μm wide. Pleurocystidia absent. Caulocystidia (23 –) 28–44 (– 48) × 15–26 (– 27) μm, all are lecythiform (body lageniform, broadly ellipsoid to oblong, some subglobose), capitula 7–16 μm wide. Pileipellis epithelioid hymeniderm, composed of spheropedunculate and clavate cells (23 –) 27–48 (– 53) × (11 –) 12–24 μm, basal pigments clay brown (RAL 8003) to olive brown (RAL 8008). Pileocystidia (29 –) 32–53 (– 54) × (5 –) 7–13 (– 15) μm, all are lecythiform to tibiiform (body lageniform, broadly ellipsoid to oblong, partially fusiform to cylindrical), capitula 4–8 μm wide, some pigment-filled. All structures with clamp connections. Weakly positive reaction to ammonia, forming needle-shaped crystals. Habitat. Scattered growth on plateau grasslands in summer. Known distribution. Xizang Autonomous Region, Xigazê City, China. Additional collection examined. China • Xizang Autonomous Region, Xigazê City, Chomo County, 24 July 2025, 27°37'12"N, 88°56'24"E, alt. 3607 m, S. M. Tang, 2025072428 (FJAU 78853). Notes. Based on the presence of exclusively lecythiform caulocystidia, C. maculatostriata belongs to sect. Conocybe. Within this section, its assignment to the ser. Magnicapitata Hauskn. & Krisai is justified by the notably large capitula of its lecythiform cystidia, which, based on existing species descriptions, range from 4–18 μm (Hausknecht and Krisai-Greilhuber 2006). Conocybe maculatostriata differs from C. spiculoides Kühner & Watling in ser. Magnicapitata, as the latter lacks a germ pore on its basidiospores and has basidiospores less than 9.5 μm long (Watling 1980). It is distinguished from C. echinata (Velen.) Singer and C. rickeniana P. D. Orton, as both have notably shorter basidiospores (average length <10 μm) and a negative reaction to ammonia (Orton 1960; Singer 1989). Conocybe maculatostriata differs from C. proxima Singer in that the latter has basidiospores shorter than 9 μm (6.8–8.6 μm) and grows on decaying wood (Singer and Digilio 1951). The new species can be distinguished from C. juniana (Velen.) Hauskn. & Svrček, inclusive of its var. sordescens (P. D. Orton) Hauskn. & Svrček, and var. subsejuncta Hauskn. by the latter indistinctly striate pileus and rugose pileus surface (Hausknecht 2009). Conocybe maculatostriata differs from C. amazonica Singer in that the latter has 13.5–15.5 μm long basidiospores, and grows on wood blocks in the Amazon rainforest (Singer 1989). Phylogenetically, C. maculatostriata is closely related to C. coniferarum and C. yadongensis R. L. Zhao & X. X. Han. However, C. coniferarum has slightly smaller, 8.5–10 μm, lentiform basidiospores, a negative reaction to ammonia, and grows in coniferous forests, while C. yadongensis has basidiospores shorter than 10 μm (8.4–9.1 μm), and a brownish orange to yellowish brown pileus without maculate stripes (Malysheva 2017; Han et al. 2025).
Institution: Dali University
Language: English
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7204235333