Conocybe hexagonospora Métrod ex Hauskn. & Enderle

Conocybe hexagonospora Métrod ex Hauskn. & Enderle View in CoL

Figs 2 N – P View Figure 2 , 9 View Figure 9 , 10 View Figure 10

Description.

Basidioma mycenoid. Pileus diameter 1.0– 1.5 cm, obtusely conical, edge straight, undulate, center signal brown (RAL 8002) to deer brown (RAL 8007), fading towards the edge, brown beige (RAL 1011) to ivory (RAL 1014), pileus hygrophanous, smooth, striate towards the center. Context thin, ivory (RAL 1014) to light ivory (RAL 1015), no specific odor or taste. Lamellae adnexed to narrowly adnate, ventricose, slightly loosely, unequal in length, beige (RAL 1001) to sandy yellow (RAL 1002), with smooth margins. Stipe length 3.5–4.0 cm, width 0.5–1.5 mm, cylindrical, brown beige (RAL 1011) to sandy yellow (RAL 1002), surface pubescent, longitudinally fibrous striate, subbulbous at the base.

Basidiospores (40 / 1 / 1) 7.5–9.5 (– 10) × 5.5–6.5 × 5–6 μm, Q = (1.32 –) 1.34–1.78 (– 1.80), Qm = 1.49 (± 0.11), lentiform, frontal view nearly hexagonal or submitriform, side view ellipsoid to oblong, thick-walled, containing oil droplets, germ pore diameter 0.5–1.5 μm. Basidiospores in 5 % KOH solution ochre brown (RAL 8001) to copper brown (RAL 8004). Basidia (14 –) 15–21 (– 22) × 8–10 μm, broadly clavate to clavate, 4 - spored, with sterigmata length 3–6 μm, basidia contain vacuolar contents. Cheilocystidia (13 –) 15–21 × 7–10 (– 11) μm, lecythiform, with capitula 3–6 μm wide. Caulocystidia are ellipsoid to oblong, lageniform, long-necked lageniform, nettle hair-shaped, narrowly conical, fusiform, cylindrical, clavate, narrowly utriform to utriform, measuring (20 –) 22–55 (– 57) × (5 –) 6–16 μm, capilliform cystidia can reach a length of 100 μm, with rare lecythiform cystidia mixed in. Pileipellis hymeniform, consists of spheropedunculate and obpyriform cells, 29–48 (– 50) × (18 –) 19–27 (– 30) μm, with yellow pigment at the base. Pileocystidia are rare and lageniform in shape. All tissues exhibit clamp connections. It shows a negative reaction to ammonia solution.

Habitat.

Solitary in mixed forests during autumn.

Known distribution.

Asia: China, Russia; Europe: Sweden, Finland, Latvia, Hungary, Germany, Austria (Holotype), Belgium, United Kingdom, France, Italy ( Hausknecht 2009).

Additional specimens measured.

China, • Jilin Province, Siping City , Yitong Manchu Autonomous County, 7 September 2023, 43°35'58"N, 125°12'12"E, alt. 290 m, Han-Bing Song, S 23090710 ( FJAU 71661 ) GoogleMaps .

Notes.

Although this species does not have gene sequences in the NCBI database, its macroscopic and microscopic structures are consistent with those of C. hexagonospora , leading to its identification as C. hexagonospora . There are also some species in sect. Pilosellae with basidiospores’ shapes similar to C. hexagonospora , but they are distinct species, differentiated as follows: The difference between C. hexagonospora and C. brunneidisca is that the latter has longer basidiospores, reaching a length of 9.9–12.1 μm, and the pileus color and habitat are also different ( Hausknecht and Contu 2007). The difference between C. hexagonospora and C. pulchra is that the latter has basidiospores measuring 11.5–15 μm in length and lacks pileocystidia ( Hausknecht et al. 2004). The difference between C. hexagonospora and C. lentispora is that the latter has basidiospores with a length smaller than 7 μm and are broadly ellipsoid ( Hausknecht 2005). Meanwhile, the difference between C. hexagonospora and C. brunneoaurantiaca is that C. brunneoaurantiaca has cheilocystidia reaching up to 30 μm and lacks pileocystidia ( Thomas et al. 2001). In the phylogenetic tree, C. hexagonospora and C. angulispora are sister taxa to each other, but their ITS sequence similarity is only 91 %. Conocybe angulispora has distinct pubescence on its pileus, allowing for differentiation from C. hexagonospora . Of these similar species, the following are sequenced and clearly separate in the phylogeny: C. hexagonospora , C. brunneidisca , C. angulispora .