Ramariopsis nivea J. L. Wei & T. Bau, 2025

Wei, Jun-Lin & Bau, Tolgor, 2025, Two new species of Ramariopsis (Clavariaceae, Agaricales) from Jilin Province, China, Phytotaxa 705 (1), pp. 75-85 : 80

Ramariopsis nivea J. L. Wei & T. Bau , sp. nov. ( Figure. 4 and 5 )

MycoBank number: —856792

Diagnosis: — Ramariopsis nivea basidiomata completely white, the primary branches densely arranged and seemingly connate together, branches crowned, basidiospores subglobose to broadly ellipsoidal, with regular and minute wart-like ornamentation on the surface (0.1–0.2 μm).

Etymology: — “nivea ” refers to the basidiomata completely white.

Type: — CHINA. Jilin Province: Jilin, Huadian City, Hongshi National Forest Park, 42°49′N, 127°8′E, 511.5 m, T. Bau & Rihong Lin ( FJAU 72016, holotype!). Jilin Jiaohe City, Hongye Valley, 18 August 2024, T. Bau & Mu Liu ( FJAU 72017, paratype!).

Description: —Basidiomata 10–50 mm high, 10–38 mm wide, arbuscular. Surface white (1A1). Polychotomous, irregularity. The primary branches densely arranged and seemingly connate together, forming a fan-shaped secondary branching that is extremely dense. Axil "V"-shaped. Internodes disminshing gradually, short cylindrical. Apex narrowly rounded or dichotomous. The stipe strong, up to 15 mm tall and 5 mm wide, constituting up to 1/5–1/3 of the total basidioma height, concolourous with branches, being thick at the base and tapering upwards, surface smooth and covered with a white downy layer at the base. Context fragile and white. Odour and taste not distinctive. Macrochemical reactions: FCL test on hymenium negative. Dry basidiomata totally white.

Basidiospores (60/2/2) (3.6–)3.7–4.2(–4.6) × (3.3–)3.4–3.6(–3.9) μm, Q=(1.04–)1.07–1.18(–1.29), sub-globose to broadly ellipsoidal and ornamentated with verruculose or nearly wart on the surface, ornamentation are smaller and regular (up to 0.2 μm), with an big drip, hyaline in KOH. Basidia 20–31(–33) × 6–7 μm, cylindrical, 4-spored, sterigmata 2–4 μm long, base with clamped connections. Hymenium 23–35 μm thick. Subhymenium 6–11 μm thick. Tramal hyphae monomitic, hyaline, thin walled, with clamps. Hyphae of branches parallel, cells 1.6–6.9 μm in diameter, rarely inflated up to 12.8 μm, with clamps present. Hyphae of the stem 2–7.3 μm wide, often containing inflated cells diameter up to 14 μm.

Habitat: —Gregarious, terrestrial, growing directly on humus-covered soil in broad-leaved forests(dominant plant species of Acer sp. , Juglans mandshurica , Quercus mongolica , etc.) in summer and autumn.

Distribution: —Currently known in Jilin Province, China, Asia.

Additional specimen examined: — CHINA. Jilin Province: Jilin, Jiaohe City, Lushui River National Forest Park, 25 August 2024, T. Bau & Xianyan Zhou (FJAU72018).

Figures

FIGURE 4. a. Basidiomata of Ramariopsis nivea (FJAU72016, holotype); b. Basidiomata of Ramariopsis nivea (FJAU72017, paratype); c. Basidiospores under optical microscope; d. Basidiospores under SEM, 15.00K ×. Scale bars: (a, b=10 mm; c=5 µm; d=1 µm).

FIGURE 5. Illustration of Ramariopsis nivea a. Basidiomata, b. Basidiospores, c. Basidia, Scale bars: (a=10 mm; b=3 µm; c=7 µm)