Russula brevipileocystidiata X.Y. Sang & L. Fan, 2016

Sang, Xiaoyu, Li, Xuedong, Wang, Yanwei & Fan, Li, 2016, Four new sequestrate species of Russulaceae found in China, Phytotaxa 289 (1), pp. 101-117 : 110-112

Russula brevipileocystidiata X.Y. Sang & L. Fan , sp. nov. ( Fig. 5 , Fig. 7C )

Mycobank: MB819370

Type:— CHINA. Sichuan: Panzhihua City, in soil under mixed woodlands dominated by P. yunnanensis , 23 Nov 2014, CJZ 1539-1, FAN 455 ( BJTC!), collected by J. Z. Cao (Holotype: BJTC FAN 455).

Basidioma 15 × 13 mm, irregularly globose. Peridial surface yellow white, glabrous, with unconspicuous ridges and furrows. Gleba pale brown, very irregular loculate, locules compacted, slightly labyrinthine. Stipe absent. Columella absent. Latex absent. Smell unremarkable.

Basidiospores globose, 8–12 μm diam. (x = 10.2 ± 1.2, n = 30) excluding ornamentation, Q = 1.00–1.20, colorless to yellowish-brown, slightly thick-walled, completely dissociated after mature, ornamentation strongly amyloid, composed of isolated, conical spines 1–2.5 μm long, slightly broad at base. Hilar appendix usually conspicuous, 2–3.5 μm long, central, cylindrical or conical, straight or slightly curved. Basidia 20–60 × 4–10 μm, clavate to broadly clavate, broadly cylindrical or ventricose, hyaline, mostly 2–4-spored, the sterigmata up to 3–9 μm long. Pseudocystidia 35–57 × 4–7 μm, subclavate to clavate with rounded apices, patchily abundant, arising in trama, not extending beyond basidia. Cystidia absent. Hymenophoral trama 13–70 μm wide, composed of interwoven, hyaline hyphae 2.5–5 μm diam., laticiferous hyphae 2.5–6.5 μm diam., sphaerocytes absent; subhymenium 6–15 μm wide, composed of pseudoparenchyma with 1–2 tiers of isodiametric cells 6–16 × 3–12 μm. Peridiopellis two-layered: a thin suprapellis composed of repent to erect cystidia 11–37 μm, cylindrical or clavate, with yellowish refractive content; subpellis 40–70 μm thick, composed of irregular, agglutinated pseudoparenchyma with 5–7 tiers of cells 7–20 × 5–12.5 μm. Peridial context 75–200 μm wide, composed of loosely interwoven, hyaline hyphae 2–4 μm diam., and scattered laticiferous hyphae with refractive granular content, 2–5 μm diam., sphaerocytes absent.

Diagnosis:— Basidioma 15 × 13 mm, irregularly globose. Peridial surface yellow white, glabrous. Gleba pale brown, very irregular loculate. Columella absent. Basidiaspores globose, with isolated spines. Basidia mostly 2–4- spored. Pseudocystidia present. Cystidia absent.

Etymology: —Latin, brevipileocystidiata = short pileocystidia, in reference to the short cystidia in the suprapellis.

Habit, habitat and distribution: —hypogeous, gregarious, in soil under mixed woodlands dominated by P. yunnanensis in Sichuan Province, China.

Commentary: — Russula brevipileocystidiata is distinguished from other species of the genus Russula by the short repent to erect cystidia in suprapellis, the laticiferous hyphae with refractive granular content in peridial context, and the globose basidiospores with isolated, conical spines. Three other species, C. clavatum T. Lebel ( Lebel 2003: 375) , C. macrocystidium T. Lebel ( Lebel 2003: 380) and C. trappei T. Lebel ( Lebel 2003: 392) are somewhat similar to this new species. However, C. clavatum differs by its rostrum apices of hymenial cystidia and the stipe-columella; C. macrocystidium lacks hymenial cystidia and its basidiomata have brown or reddish to orangish streaks in the furrows. Cystangium trappei is distinguished from R. brevipileocystidiata by its golden yellow gleba and the long peridial cystidia (35–125 μm long) ( Lebel 2003).

Figures

FIGURE 5. Russula brevipileocystidiata (BJTC FAN455, holotype).A. Basidia. B. Pseudocystidia. C. Basidiospores. D. Peridiopellis and peridial context. E. Hymenophoral trama and hymenium. Scale bar = 10 μm.

FIGURE 7. Scanning electron micrograph (SEM) of basidiospores. A. Lactarius spinosporus (holotype). B. Russula absphaerocellaris (holotype). C. Russula brevipileocystidiata (holotype). D. Russula megapseudocystidiata (holotype). Scale bar = 5 μm.