Catathelasma laorentou Z.W. Ge, 2020

Ge, Zai-Wei, Wu, Jian-Yun, Hao, Yan-Jia, Zhang, Qingying, An, Yi-Feng & Ryberg, Martin, 2020, The genus Catathelasma (Catathelasmataceae, Basidiomycota) in China, MycoKeys 62, pp. 123-138 : 123

Catathelasma laorentou Z.W. Ge sp. nov. Figs 2A , 3

Diagnosis.

This species is distinguished from C. ventricosum (Peck) Singer by having pale yellow to greyish-yellow basidiomes, longer stipes, abundant clamp connections and associations with Pinus yunnanensis Mast. and Keteleeria evelyniana Franchet in south-western China.

Type.

China. Yunnan Province: Chuxiong, Zixi Mountain, alt. 1950 m, in forest dominated by K. evelyniana Mast. and P. yunnanensis Franchet, 26 August 2017, Z. W. Ge 4070 (Holotype: HKAS 105984). GenBank accession numbers: - ITS, MK909107.

Description.

Pileus 10-24 cm broad, hemispherical to convex at first, expanding to convex to broadly convex with age; surface initially white, then yellowish-white (1A2) to pale yellow (1A3), greyish-yellow (2B3) with age, smooth at first, irregularly depressed, margin more or less incurved, slightly viscid to viscid when wet, occasionally with whitish veil remnants. Lamellae decurrent, white to off-white when young, whitish when mature, thick, 7-15 mm in height, with 1-2 series of lamellulae, edge smooth. Stipe 6-24 × 1.5-8 cm, fusiform, attenuate downwards, straight or curved, firm, with double annulus in which the lower annulus is flimsy and the upper annulus is membranous to leathery, yellowish-white, often split into several pedals. Context white, 2.1-4.5 cm thick in pileus, white in pileus and stipe, not changing colour when cut; smell and taste farinaceous. Spore print white.

Basidiospores [70/3/3] (8) 9-12(15) × (4) 5-6.5 (7) μm (mean 9.9 ± 1.3 × 5.8 ± 0.5 μm), Q = (1.23) 1.33-2.2 (2.75), Qav = 1.72 ± 0.30, ellipsoid, oblong to subcylindrical in frontal view, subcylindrical to somewhat inequateral in side view, hyaline in KOH, amyloid, congophilous, smooth, thin walled, without germ pore. Basidia 38-50 × 8-10 μm, narrowly clavate, 4-spored, hyaline; sterigmata up to 6 μm long. Cheilocystidia basidiole-like, hyalinous. Pleurocystidia absent. Lamella trama subregular, somewhat bilateral towards lamella edge, made up of more or less parallel to interwoven hyphae. Oleiferous hyphae present in both lamella and pileus trama. Pileipellis a thick ixocutis (850-1000 μm thick) of loosely interwoven cylindrical, gelatinised hyphae 2-10 μm in width, interspersed with oleiferous hyphae. Clamp connections present, common.

Distribution.

Known from Sichuan and Yunnan provinces in south-western China.

Ecology.

Presumably ectomycorrhizal, solitary or scattered, rarely in small clusters of 2-5 basidiomes in Pinus or Keteleeria forests.

Etymology.

From 'lao ren tou jun’, a transliteration of the Chinese name “老人头菌” which is a local common name used in the wild mushroom markets in Yunnan, China. The literal translation is "fungus that looks like the shiny bald pate of The God of Longevity".

Additional specimens examined.

China. Yunnan Province, Chuxiong, Nanhua, wild mushroom market, 12 August 2014, Z. W. Ge 3620 (HKAS 84458); Dali, Bingchuan, Jizu Mountain, alt. 2350 m, 4 August 2013, J. Qin 728 (HKAS 81166); Kunming, Aziying, 15 August 2015, Z. W. Ge 3765 (HKAS 92245); Kunming, Yeyahu, alt. 2000 m, 22 September 2012, L. H. Han 23 (HKAS 78582); Lijiang, Ninglang, alt. 2300 m, in Pinus yunnanensis forest, 6 August 2011, T. Guo 368 (HKAS 71264); Sichuan Province: Muli, Liziping, alt. 2500 m, in Pinus yunnanensis forest, 31 July 2012, Y. J. Hao 688 (HKAS 76346).

Discussion.

Catathelasma laorentou is morphologically similar to C. ventricosum (Peck) Singer, a species originally described from North America. Both species have ellipsoid basidiospores, large-sized hemispherical pilei and a pileipellis composed of an ixocutis layer. However, C. laorentou has abundant clamp connections, smaller basidiospores (9-11 × 5-6 μm), larger basidia (38-50 × 8-10 μm) and is found in coniferous forest dominated by P. yunnanensis and K. evelyniana from south-western China, while C. ventricosum is found alongside hardwood ( Singer 1940).

Catathelasma singeri Mitchel & A.H. Sm. from the USA is morphologically similar to C. laorentou , but the former differs by its dull pale ochraceous to dingy olive buff pileus which is slimy viscid and shows similarities to Hygrophorus Fr., smaller basidiomes (pileus around 6 cm, stipe 4 × 1.2 cm), bearing basidiole-like or narrower cheilocystidia. Catathelasma singeri was collected from the aspen zone, which was dominated by Populus tremuloides and Pinaceae species, although the specific host tree was not mentioned ( Mitchel and Smith 1978).

Catathelasma imperiale , originally described from Europe, is distinguished by its greyish-brown, reddish-brownish or brown basidiomes (Fig. 2C, D ), cylindrical cheilocystidia with yellow contents and its association with species of Pinus , Picea and Abies ( Læssøe and Petersen 2019; Vellinga 1999; personal observation by the first author).

Figures

Figure 2. Basidiomes of Catathelasma species in China. A Catathelasma laorentou (HKAS 92245) B Catathelasma subalpinum (HKAS 67751) C Catathelasma imperiale (HKAS 79952) D Young Catathelasma imperiale (HKAS 84299) in association with roots of Picea asperata Mast. Scale bars: 2.5 cm.

Figure 3. Microscopic features of Catathelasma laorentou (HKAS 105984) A Basidiospores B Basidia C Pileipellis. Oleiferous hyphae are indicated by thick-walled hyphae. Scale bars: 10 μm.