Russula pseudobubalina, 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 : 271-272

Russula pseudobubalina sp. nov. J. W. Li & L. H. Qiu, ( Fig. 2 d–f , Fig. 4 )

Mycobank: MB 825624

Etymology: —Refers to its similarity to Russula bubalina .

Holotype:— Collected from Dinghu Mountain , Zhaoqing City, Guangdong Province, CHINA, 7 June 2015, J. W. Li and J. B. Zhang K15060707 ( GDGM70632 ).

Basidiomata small to medium sized. Pileus 3.1–4.6 cm, convex when young, planoconvex to applanate when matured, surface dry, cinnamon buff on the center (# FFCC 66), a little shading to margin, margin acute, glabrous, striate with age, not peeling readily. Context firm, 2–3.5 mm thick, white, purplish red with FeSO 4, mild tasted, color unchanged when bruised, yellow when dry. Lamellae adnate, white, unchanging when bruised, equal, with lamellulae, never forked, 2.5–3.5 mm wide, compacted, 18–19 pieces per 1 cm at middle, inter-veined, cream when dried. Stipe white, equal, 2.3–3.1 × 0.8–1.1 cm, terete, smooth, stuffed. Odour indistinct. Spore print white.

Basidiopores [60/3/2] subglobose to broadly ellipsoid, (5.4) 5.8– 6.2 –7.0 × 4.7–5.3–5.9 μm. Q= (1.05) 1.09– 1.17 –1.25 (1.35), Qm= 1.17 ± 0.08, ornamentation composed of mostly amyloid warts, measuring 0.3–0.5 μm high, rarely connected by scattered lines, suprahilar area not amyloid. Basidia clavate to fusiform, 27.3– 37.7 –46.4 × 8.7– 11.4 –15.6 μm, mostly with four sterigmata, two or three sterigmata also present, hyaline, sterigmata 2–6 μm long. Lamellar trama mainly consist of large sphaerocytes. Pleurocystidia measuring 37.3– 60.6 –89.6 × 7.6– 9.7 –12.4 μm, abundant, projecting 12–20 μm beyond the hymenium, clavate-pedicellate to narrowly fusiform with mucronate to moniliformous appendiculate, obtuse apex rarely observed, with abundant heteromorphous contents, mostly with slightly thickened walls, slightly becoming brown in SV. Cheilocystidia mostly clavate, fusiform with mucronate-appendiculate also present, measuring 23.4– 37.8 –65.5 × 6.2– 8.3 –10.0 μm, with abundant refractive contents, also slightly becoming brown in SV. Pileipellis orthochromatic in Cresyl blue, vaguely divided in a 100–120 μm deep suprapellis, of ascending to erect hyphal endings and pileocystidia and a 75–90 μm thick subpellis of horizontally oriented and intricate hyphae. Terminal elements attenuate subcylindrial, wall slightly thickened, measuring 17.5– 25.3 –36.7 (43.7) × 2.8– 3.4 –3.9 μm, originating from branched or subcylindrial subapical cells. Pileocystidia oriented in suprapellis, measuring 22.3– 34.4 –47.6 × 3.5– 4.6 –5.7 μm, one-celled, most clavate or subcylindrical, some with moniliformous apex, filled with abundant refringent contents, negative with SV. Stipitipellis a cutis measuring 80–110 μm wide, with interwoven hyphae, thin-walled, hyaline, cylindrical. Caulocystidia ca. 25.3– 36.4 –45.3 × 3.5– 4.7 –6.7 μm, attenuate clavate to fusiform, obtuse to mucronate apex. Clamp connection absent from all tissues.

Diagnostics:—Closely related to Russula bubalina macro-morphologically, but it can be recognized by its unforked lamellae, shorter cheilocystidia, bigger basidia and basidiospores with lower ornamentations.

Habitat and distribution: —collected from 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. B. Zhang ( GDGM 70631).

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 4. Russula pseudobubalina (Holotype GDGM70632). a. Basidia; b. Cheilocystidia; c. Pleurocystidia; d. Pileipellis; e. Pileocystidia; f. Caulocystidia. Scale bars= 10 μm.