Clavariadelphus khinganensis J. Zhao, L.P. Tang & P. Zhang, 2020

Huang, Hong-Yan, Zhao, Jie, Zhang, Ping, Ge, Zai-Wei, Li, Xian & Tang, Li-Ping, 2020, The genus Clavariadelphus (Clavariadelphaceae, Gomphales) in China, MycoKeys 70, pp. 89-121 : 89

publication ID	https://dx.doi.org/10.3897/mycokeys.70.54149
persistent identifier	https://treatment.plazi.org/id/14004616-12B2-5647-B537-B3A48FAB573D
treatment provided by	MycoKeys by Pensoft
scientific name	Clavariadelphus khinganensis J. Zhao, L.P. Tang & P. Zhang
status	sp. nov.

Treatment

6. Clavariadelphus khinganensis J. Zhao, L.P. Tang & P. Zhang sp. nov. Figs 2h-i View Figure 2 , 3f View Figure 3 , 4g View Figure 4 , 11a, b View Figure 11

Diagnosis.

This species is distinct from other taxa in Clavariadelphus by the yellowish-brown, clavate basidiomes with slightly enlarged apex, narrowly ellipsoid basidiospores and basidiomes that turn very light yellow in KOH.

Etymology.

Latin " khinganensis " refers to the holotype location, Greater Khingan Mountains or Da Xing’an Ling, in NE China.

Description.

Basidiomes up to 12.5 cm high, around 0.8 cm diam. basally, 2.5 cm diam. apically, simple, initially subcylindrical to subfusiform, enlarged upwards in age, then clavate to broadly clavate, finally irregularly laterally compressed; hymenium initially smooth, longitudinally rugose to rugulose in age, pale yellow-brown (4A3) or pale orange (5A 4-6) to greyish-orange (5B4-5, 6B4-5); apex obtuse or broadly rounded, rugose, concolorous with the hymenium at maturity; base terete, smooth, white to pallid when covered, otherwise pale yellow (4A4-5) to light orange (5A4-6); mycelial hyphae interwoven, white; flesh initially solid, becoming soft and spongy upwards as the apex enlarges in age, dirty white. Odour and taste not recorded. Spore deposit not recorded.

Hymenium extending over the apex of basidiomata, composed of basidia and leptocystidia. Basidia 85-105 × 8-11 μm, clavate, hyaline, thin-walled, 4-spored, sterigmata 9-10 μm in length. Basidiospores [20/1/1] 9.2-12.0 × 4.6-6 μm, Q = 1.6-2.2, Q m = 1.97 ± 0.17, narrowly ellipsoid or amygdaliform, with a small apiculus, inamyloid, thin-walled, hyaline in KOH, smooth. Leptocystidia 60-70 × 3-4 μm, scattered amongst and scarcely projecting beyond the basidia, cylindrical to narrowly clavate, thin-walled, smooth, hyaline, non-pigmented, clamped, inflated apically at maturity, at times with apical or subapical branches. Mycelial hyphae lacking material.

Chemical reactions.

(dried basidiomes): KOH = positive, very light yellow; ethanol, FeCl3, FeSO4, phenol, Melzer’s reagent and NH4OH = negative.

Known distribution and ecology.

N China. Solitary on the ground in broad-leaved forests at around 800 m altitude.

Materials examined.

CHINA. Jilin Province: Antu Prefecture, Er-dao-bai-he Town, Changbai Mountains, mainly broad-leaved forests ( Betula platyphylla , Corylus mandshurica , and Quercus monimotricha ), mixed with the coniferous tree ( Pinus koraiensis ), 42°24.05'N, 128°6.00'E, alt. 753 m, 18 August 2019, H.Y. Huang 368 (MHKMU H.Y. Huang 368). Inner Mongolia: De-er-bu-er Town, Greater Khingan Mountains, alt. 800 m, 6 August 2013, P. Zhang 1289 (MHHNU 7789 Holotype); Ku-ti-he Town, Zha-lan-tun City, 24 July 1985, W. Huang s. n. (HMAS 49920).

Comments.

Clavariadelphus khinganensis , known from broad-leaved forests in N China, is distinct by its solitary habit at low elevations (around 800 m), small size, pale brown-orange basidiomes, ellipsoid basidiospores and very pale yellow reaction in KOH.

Morphologically, C. khinganensis is quite similar to two Asian taxa, C. mirus and C. yunnanensis . However, C. mirus was originally described from northern Vietnam and has larger basidiomes, broader basidiospores and a tropical distribution (Butan, India, Nepal; Methven 1990). Clavariadelphus yunnanensis is unique in its habit, growing with conifers at high elevations (above 3000 m), has darker colouration and larger basidiomes (up to 20 cm high), broader basidiospores and basidiomes with yellow reactivity in KOH.

Interestingly, C. khinganensis is clustered with a collection labeled as " C. truncatus " from Canada, the GenBank accession DQ097871 ( Durall et al. 2006) and there are no genetic differences on ITS (Fig. 1 View Figure 1 ). It indicates C. khinganensis may be distributed in Canada. More data from North America are needed to confirm the distribution pattern of this species. The sister relationship of C. khinganensis cannot be resolved according to the present data.