Collybiopsis subumbilicata J.S. Kim & Y.W. Lim, 2022

Kim, Ji Seon, Cho, Yoonhee, Park, Ki Hyeong, Park, Ji Hyun, Kim, Minkyeong, Kim, Chang Sun & Lim, Young Woon, 2022, Taxonomic study of Collybiopsis (Omphalotaceae, Agaricales) in the Republic of Korea with seven new species, MycoKeys 88, pp. 79-108 : 79

Collybiopsis subumbilicata J.S. Kim & Y.W. Lim sp. nov.

Fig. 4A, B

Etymology.

Epithet " Collybiopsis subumbilicata " referring to having a small depressed center in pileus.

Holotype.

The Republic of Korea, Seoul, Gwanak-gu, Mt. Gwanak, 37°12'39"N, 128°19"E, alt. 877 m, 01 July 2014, Young Woon Lim, SFC20140701-03 (GenBank accession no. ITS: OL467232; nrLSU: OL462787).

Diagnosis.

The distinctive features include a brownish, 10-35 mm pileus, white colored lamellae, a brownish, 25-60 × 1-3 mm stipe covered with pubescence, ellipsoid to oblong basidiospores, narrowly clavate and cylindrical, 17-24.3 × 3.5-5.1 μm basidia, and cylindrical, flexuose, sometimes curved, 12.6-38.2 × 2.4-6.6 μm caulocystidia.

Description.

Pileus: 10-35 mm, plano-convex to plano-concave, subumbilicate, becoming undulate and uplifted in age; Surface smooth, greyish orange (5B3) to brown (6E5). Lamellae: subdistant, L = 22-38, l = 3-7, free to adnexed, white. Stipe: 25-60 × 1-3 mm, cylindrical, tomentose, hollow, light brown (7D4) to dark brown (9F8), becoming paler to the apex, covered with pubescence. Basidiospores: 5.5-7.5 × 2.5-3.6 μm (average 6.47 × 3.0 μm), Q = 1.8-2.2 (mean = 2), oblong to fusiform, smooth, hyaline, non-dextrinoid, with drops. Basidia: (15.6) 17-24.3 (27.6) × 3.5-5.1 (5.9) μm, 4-spored, narrowly clavate, cylindrical. Cheilocystidia: 17.6-38.4 × 5-7.8 μm, various in shape, lobed. Pleurocystidia: 20.3-30.7 × 6.8-9.5 μm, clavate, fusiform, slightly sphaeropedunculate. Trama hyphae: cylindrical, subinflated, branched, smooth, non-dextrinoid, 1.5-8 μm wide. Pileipellis: a cutis made up of cylindrical, often incrusted, with heavy annular ornamentation, 5.0-15 μm wide hyphae; terminal elements adpressed to suberect, fusoid, clavate, 6.0-16 μm wide. Stipitipellis: a cutis of cylindrical, smooth, thin-walled, 2.0-6.0 μm wide hyphae. Caulocystidia: 12.6-38.2 × 2.4-6.6 μm, cylindrical, flexuose, sometimes irregular or curved. Clamp connections: present in all tissues.

Other specimens examined.

The Republic of Korea, Gangwon-do: Goseong-gun , Hwajinpo , Hwajinpo Condominium , 38°28'24"N, 128°26'30"E, alt. 7 m, 2 August 2012, Young Woon Lim, SFC20120802-03. The Republic of Korea, Gyeongsangbuk-do: Ulleung-gun, Ulleung island , 37°30'38"N, 130°51'44"E, alt. 429 m, 22 August 2017, Jae Young Park, Nam Kyu Kim, SFC20170822-14 .

Habit and habitat.

Scattered to gregarious on the ground covered with dead leaves in temperate mixed forests, from summer to autumn.

Distribution.

The Republic of Korea.

Remark.

Collybiopsis subumbilicata appears similar to Co. villosipes (Cleland) R.H. Petersen. Collybiopsis villosipes is distinguished from Co. subumbilicata by fewer and brownish lamellae (also lamellulae), a noninsititious, light-colored stipe, larger basidiospores (6.5-10.5 × 3.5-4.5 μm) and basidia (25-34 × 6.5-7.5 μm) ( Desjardin et al. 1997). Furthermore, Co. subumbilicata is phylogenetically close to Co. biformis and Co. disjuncta (R.H. Petersen & K.W. Hughes) R.H. Petersen & K.W. Hughes. Collybiopsis biformis is morphologically similar to Co. subumbilicata but can be distinguished by elongated basidiospores (6.4-9.2 × 2.4-4.8 μm), thicker basidia (6-7 μm thick) and cheilocystidia (6-12 μm thick) ( Morgan 1905; Mata 2002). Collybiopsis disjuncta can be distinguished from Co. subumbilicata by a smaller pileus (7-12 mm) with olivaceous tint, pinkish lamellae, slender stipe (0.5-1 mm thick), bigger basidiospores (6-7.5 × 3-3.5 μm), bigger basidia (22-34 × 5-7 μm), and a seldom incrusted pileipellis ( Petersen and Hughes 2014).

Figures

Figure 4. Basidiomata and microscopic characters of the three new Collybiopsis species A, B Co. subumbilicata (SFC 20120802 - 03) C, D Co. undulata (SFC 20150813 - 04) E, F Co. vellerea (SFC 20140821 - 29). Scale bars: 1 cm (A, C, E); 20 µm (B, D, F). Abbreviations: s basidiospores; b basidia; ch cheilocystidia; p pleurocystidia; ca caulocystidia.