Conocybe angulispora T. Bau & H. B. Song, 2025

Song, Han-bing & Bau, Tolgor, 2025, Three new species and a new record of Conocybe section Pilosellae (Bolbitiaceae, Agaricales) from Jilin Province, China, MycoKeys 114, pp. 67-94 : 67-94

Conocybe angulispora T. Bau & H. B. Song sp. nov.

Figs 2 E – H , 5 , 6

Etymology.

“ angulispora ” refers to basidiospores that are angular and submitriform or slightly hexagonal in shape.

Holotypus.

China, • Jilin Province, Jilin City, Jiaohe City, Shansongling , 26 August 2023, 43°32'25"N, 127°02'21"E, alt. 550 m, Hong Cheng, C 2382612 ( FJAU 65120 ) .

Diagnosis.

Conocybe angulispora basidiospores are lentiform, frontal view slightly hexagonal or submitriform, side view ellipsoid to oblong, ovoid, amygdaliform, basidia are 4 (2) - spored, and pileocystidia are abundant.

Description.

Basidioma mycenoid. Pileus diameter 0.5–2.5 cm, initially paraboloid to obtusely conical, later conical to broadly conical, edge straight, undulate. In early stages, pileus center color ranges from signal brown (RAL 8002) to mahogany brown (RAL 8016), with slightly lighter color at the edges, brown beige (RAL 1011), sandy yellow (RAL 1002) to maize yellow (RAL 1001). When mature, pileus center color changes to reddish-brown (RAL 8012) to mahogany brown (RAL 8016), while the edge remains brown beige (RAL 1011) and ivory (RAL 1014). Pileus hygrophanous, distinctly pubescent, with striations extending to the center. Context thin, ivory (RAL 1014) to light ivory (RAL 1015), no specific odor or taste. Lamellae adnexed to narrowly adnate, ventricose, slightly crowded, unequal in length, sandy yellow (RAL 1002) to ochre brown (RAL 8001), with smooth edges. Stipe length 2.5–5.0 cm, thick 1.0–2.0 mm, cylindrical, light ivory (RAL 1015), sandy yellow (RAL 1002) to signal brown (RAL 8002), surface covered with pubescent, longitudinally fibrous striations, subbulbous base.

Basidiospores (60 / 3 / 3) 8–10 (– 10.5) × 5.5–6.5 × (4.5 –) 5–6 μm, Q = (1.35 –) 1.39–1.76 (– 1.83), Qm = 1.57 (± 0.11), lentiform, angular and submitriform or slightly hexagonal in frontal view, ellipsoid to oblong, ovoid, or amygdaliform in side view, with partially thick walls and containing oil droplets, germ pore diameter 0.5–2.0 μm, basidiospores in 5 % KOH solution ochre brown (RAL 8001) to copper brown (RAL 8004) in KOH. Basidia 14–24 (– 25) × (8 –) 9–11 (– 12) μm, broadly clavate to clavate, 4 (2) - spored, sterigmata 2–6 μm long, basidia with vacuolar contents. Cheilocystidia 13–22 × 6–10 (– 11) μm, lecythiform, with capitula 3–6 μm wide. Caulocystidia ellipsoid to oblong, lageniform, long-necked lageniform, nettle hair-shaped, narrowly conical, fusiform, cylindrical, clavate, narrowly utriform to utriform, (10 –) 11–42 (– 45) × (4 –) 5–9 μm, capilliform cystidia can exceed 100 μm, among which rare lecythiform cystidia are mixed at the apex. Pileipellis hymeniform, composed of (25 –) 28–62 (– 66) × 15–34 (– 36) μm broadly clavate, spheropedunculate, and obpyriform elements, with yellow pigment at the base. Pileocystidia abundant, (22 –) 23–58 (– 60) × 5–18 (– 19) μm, lageniform to long-necked lageniform, lecythiform, tibiiform, and nettle hair-shaped, capilliform cystidia can exceed 100 μm. Clamp connections are rare in all tissues. Shows negative reaction with ammonia solution.

Habitat.

In summer, they grow scattered or in groups in the humus layer of mixed forests.

Known distribution.

Jilin Province, China.

Additional specimens measured.

China, • Jilin Province, Jilin City, Jiaohe City, Laoyeling , 28 July 2023, 43°40'57"N, 127°11'58"E, alt. 430 m, Xia Wang, W 23072815 ( FJAU 65121 ) ; • Jilin City, Jiaohe City, Shansongling , 26 August 2023, 43°32'09"N, 127°02'23"E, alt. 530 m, Hong Cheng, C 2382621 ( FJAU 65122 ) .

Notes.

In some species of section Pilosellae , the frontal view of basidiospores appears slightly hexagonal, which can be easily confused with C. angulispora . The difference between C. angulispora and C. hexagonospora is that C. hexagonospora lacks distinct pubescence on the pileus and has rare pileocystidia, making it easy to differentiate ( Hausknecht 1993). Additionally, the ITS sequence similarity between C. angulispora and C. hexagonospora is 91.2 %. Conocybe angulispora can be distinguished from C. brunneidisca by the larger length of basidiospores in C. brunneidisca , which can reach 9.9–12.1 μm, and it is found in fertile grasslands or dung ( Hausknecht and Contu 2007). Conocybe angulispora can be differentiated from C. pulchra (Clem.) Hauskn., Krisai & Voglmayr by the length of basidiospores, which measures 11.5–15 μm in C. pulchra , and C. pulchra lacks pileocystidia ( Hausknecht et al. 2004). The difference between C. angulispora and C. lentispora Singer is that the basidiospores of C. lentispora are shorter than 7 μm and broadly ellipsoid in shape ( Hausknecht 2005). Conocybe angulispora can be differentiated from C. brunneoaurantiaca K. A. Thomas, Hauskn. & Manim. such that C. brunneoaurantiaca lacks pubescence on the pileus and pileocystidia ( Hausknecht 2009; Thomas et al. 2001).

Figures

Figure 2. Basidiomata of Conocybe sect. Pilosellae species A C. verna (FJAU 65117 T) B C. verna (FJAU 65118) C, D C. verna (FJAU 65119) E, F C. angulispora (FJAU 65120 T) G C. angulispora (FJAU 65122) H C. angulispora (FJAU 65121) I C. rubrocyanea (FJAU 65123 T) J C. rubrocyanea (FJAU 71654) K C. rubrocyanea (FJAU 71658) L C. rubrocyanea (FJAU 71652) M C. rubrocyanea (FJAU 71650) N – P C. hexagonospora (FJAU 71661), Scale bars: 1 cm, T = holotype.

Figure 5. Conocybe angulispora (FJAU 65120) A basidiomata B basidiospores in KOH C hymenium and subhymenium D cheilocystidia E stipitipellis F pileipellis. Scale bars: 1 cm (A); 10 μm (B – F).

Figure 6. Microscopic structure images of Conocybe angulispora (FJAU 65120) A basidiospores B basidia C cheilocystidia D pileipellis E stipitipellis. Scale bars: 10 μm (A – E).