Russula bubalina, Li & Zheng & Song & Yuan & Qiu, 2019

Li, Jing-Wei, Zheng, Jian-Fei, Song, Yu, Yuan, Fa & Qiu, Li-Hong, 2019, Three novel species of Russula from southern China based on morphological and molecular evidence, Phytotaxa 392 (4), pp. 264-276 : 268-271

Russula bubalina sp. nov. J. W. Li & L. H. Qiu, ( Figs. 2 a–c , 3 )

Mycobank: MB 821921

Etymology: —refers to the cinnamon buff pileus.

Holotype:— Collected from Dinghu Mountain , Zhaoqing City, Guangdong Province, CHINA, 26 May 2015, J. W. Li and J. F. Zheng K15052614 ( GDGM70728 ).

Basidiomata small to medium sized. Pileus 3.5–5.4 cm, initially convex, then planoconvex to applanate, surface dry, pink (# FFCC 99) to cinnamon buff (# FFCC 66) on the center, a little shading outwards, glabrous, margin acute, even, striate with age, not peeling readily. Context firm, 2–3.5 mm wide, white, mild tasted, color unchanged when bruised, yellow when dry. Lamellae adnate, white, not changing when bruised, equal, rarely with lamellulae, forking around stipe, 2.5–3.5 mm thick, compacted, 18–19 pieces per 1 cm at middle, inter-veined, cream when dried. Stipe light pink, equal, 2.3–3.1 × 0.9–1.1 cm, terete, smooth, stuffed. Odour indistinct. Spore print white.

Basidiopores [60/3/2] subglobose to broadly ellipsoid, (4.4) 4.8– 5.7 –6.6 (8.6) × (3.7) 3.9– 4.7 –5.3 (6.2) μm. Q= 1.05– 1.21 –1.32, Qm= 1.21 ± 0.11, ornamentation composed of mostly amyloid warts, measuring 0.5–0.7 μm high, sometimes connected by scattered lines, suprahilar spot inamyloid. Basidia clavate to subcylindrical, 25.7– 31.5 –44.1 × 7.9– 10.2 –12.9 μm, mostly with four sterigmata, two and three sterigmata also present, hyaline, sterigmata 2–6 μm long. Lamellar trama mainly consist of large sphaerocytes. Pleurocystidia measuring 30.7– 60.9 –89.9 × 7.9– 9.9 –13.0 μm, abundant, projecting 12–18 μm beyond the hymenium, slender fusiform or cylindrical, with moniliform appendage or mucronate to obtuse apices, showing abundant heteromorphous contents, mostly with slightly thickened walls, brown in SV. Cheilocystidia clavate to attenuate subcylindrical-pedicellate, or sometimes with obtuse tips, rarely subfusiformpedicellate, measuring 29.1– 49.4 –86.1 × 6.2– 8.6 –10.9 μm, with abundant refractive SV-positive contents. Pileipellis orthochromatic in Cresyl blue, vaguely divided in a 40–95 μm deep suprapellis, of erect or oblique hyphal endings and pileocystidia and a 35–80 μm thick subpellis of horizontally oriented and intricate hyphae. Attenuate subcylindrial to subulate, slightly thicken walled terminal cells of suprapellis measuring 13.4– 18.8 –25.6 × 2.9– 3.9 –4.6 μm, originating from branched or subcylindrial to slightly inflated subapical cells. Pileocystidia oriented in suprapellis, measuring 20.5– 26.4 –33.3 × 2.8– 4.3 –6.2 μm, one-celled, clavate or fusiform, sometimes ventricose moniliform or with obtuse rarely mucronate apex, filled with abundant refringent contents, negative with SV. Stipitipellis a cutis measuring 60–95 μm wide, with interwoven hyphae, thin-walled, hyaline, cylindrical. Caulocystidia ca. 20.5– 32.1 –52.6 × 2.3– 3.7 –5.1 μm, attenuate cylindrical, ventricose moniliform or with obtuse apices. Clamp connection absent from all tissues.

Diagnostics: —Cinnamon buff to pink pileus with striate margin, interveined and forked lamellae, basidiospores with warty ornamentations not forming reticulum, hymenial cystidia becoming brown in sulphovanillin and slender terminal cells in suprapellis.

Habitat and distribution: —Gregarious in monsoon evergreen broadleaf forest and pine-broadleaf mixed forest.

Additional specimens examined: —Collected from Dinghu Mountain, Zhaoqing City, Guangdong Province, CHINA, 27 May 2015, J. W. Li and J. F. Zheng GDGM 70727.

Figures

FIGURE 2. Scanning Electronic Micrographs and photographs of fruiting bodies. a–c. Russula bubalina (Holotype GDGM70728); d–f. Russula pseudobubalina (Holotype GDGM70632). Scale bars: a, d= 1 cm; b–c, e–f= 10 μm.

FIGURE 3. Russula bubalina (Holotype GDGM70728). a. Basidia; b. Cheilocystidia; c. Pleurocystidia; d. Pileipellis; e. Pileocystidia; f. Caulocystidia. Scale bars= 10 μm.