Lactifluus hezhangensis W.P. Zhang, A.M. Chen & X.H. XU, 2022

Chen, A-Min, Pei, Yun, Wen, Ting-Chi, Hapuarachchi, Kalani Kanchana, Xu, Xiu-Hong & Zhang, Wan-Ping, 2022, Lactifluus hezhangensis sp. nov. (Russulaceae, Russulales) from Southwest China, Phytotaxa 575 (3), pp. 253-264 : 259

Lactifluus hezhangensis W.P. Zhang, A.M. Chen & X.H. XU , sp. nov. ( Fig 2 )

MycoBank No.: MB 840661

Type:— CHINA. Guizhou Province: Bijie City, Hezhang (27.139ºN, 104.877ºE, 1700 m), 12 July 2018, Xiuhong XU holotype HKAS 1159035 !, isotype HMAS 292389, Sequences from the strain HKAS 1159035 and HMAS 292389 have been deposited in GenBank with accession numbers: ITS= MZ621154 - MZ621155 , LSU= MZ621156 - MZ621157 , RPB2= MZ666103 - MZ666104 .

Etymology:—Refers to the collection site “Hezhang”.

Known distribution:—Hezhang, Bijie, Guizhou Province, China.

Description:— Pileus 50–55 mm diam, dry, light brown (B5651D), rough when old, most obvious at the concave; uneven color, light brown (B5651D) to blackish brown (#654321), paler toward margin; pruinose near centre, margin entire, decurved. Lamellae decurrent, white (W3C) to cream (#FFF9E3), thick and brittle, 3–5mm broad, edge concolorous to marginate, with 1–3 lamellulae located between two lamellae. The attachment to the stipe varies from adnate, adnate with a decurrent tooth to decurrent. Stipe 28–30 × 10–12 mm, hollow, dry, rough, concolorous with pileus, white at base, centralis or lateralis, tapering downwards or curved near the base. Spore deposit white. Latex white, unchanging when exposed to the air Context white (W3C) (#FFFFFF), mild.

Basidiospores (4.79) 5.06–7.22(7.30) × (4.67) 4.68–6.20 (6.59) μm; (Q= (1.01) 1.02–1.32(1.38) μm, subglobose to ellipsoid, hyaline, with a strongly amyloid ornamentation composed of interconnected warts forming a complete reticulum up to1.0 µm high. Basidia (35)37–47(48) × 9–12 μm, four-spored, sterigmata1.7–2.48μm long. Pleurocystidia absent. Marginal cells (22)23–31(33) × (3)4–7(–8) μm, Q= (3.44)3.54–7.43(7.35), Q=5.00 ± 1.50, fusoid, sometimes flexuous, thin-walled, hyaline. Hymenophoral trama subregular composed of scattered cylindrical, 2–3 μm diam, thin-walled hyphae and abundant. Pseudocystidia 5–8 μm diam. Pileipellis a palisade, 20–35 µm thick; suprapellis composed of subcylindrical to conical terminal elements, 20–47.5 × 2.5–10 µm, 1- or 4-septated, tapering towards apex, with brown; subpellis composed of 2–4 layers of cells, 10.5–16 × 9–14 µm, thin-walled. Stipitipellis a trichopalisade, 10–42 µm thick, terminal elements 9–15.5 × 2.1–5.2 µm, subcylindrical, often tapering towards apex, thin-walled, septated.

Habitat:—Gregarious, Growing on the grassland in a coniferous forest.

Specimens examined:— CHINA. Guizhou Province: Bijie City, Hezhang (N 27º08.317ʹ E 104º52.633ʹ 1700 m), on the grassland in a coniferous forest, 12 July 2018, Xiuhong XU (holotype HKAS 1159035!, isotype HMAS 292389) .

Figures

FIGURES 2. Lactifluus hezhangensis. A–B. Fresh basidiomata (holotype); C–D. SEM microphotographs, Scale bar: C–D = 2 µm, Photographs by A.M. Chen; E. Basidiospores; F. Marginal cells; G. Stipitipellis; H. Basidia; I. Pileipellis. Scale bars: E = 2 μm; G–I = 10 μm. Line drawings by X.Q. Zhou.