Ramariopsis eburnea 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 : 78-79

Ramariopsis eburnea J. L. Wei & T. Bau , sp. nov. ( Figures 2 and 3 )

MycoBank number: —856791

Diagnosis: — Ramariopsis eburnea is similar and close to R. robusta , but it differs from the latter by R. eburnea basidiomata are yellowish white, the branches are more slender, Q value is lower (1.07–1.19), the spores are subglobose to broadly ellipsoidal and ornamentated with verruculose or nearly wart on the surface, ornamentation are smaller and regular (0.2–0.4 μm), and the basidia are shorter (20–27 μm).

Etymology: — “eburnea ” refers to basidiomata ivory.

Type: — CHINA. Jilin Province: Jilin, Jiaohe City, Haiqing Forest Farm, humus-covered soil in broad-leaved forests, 43°47′N, 127°9′E, 284 m, 22 September 2024, T. Bau & Longhao Li ( FJAU 72012, holotype!). Tonghua, Liuhe County, 11 August 2022, T. Bau & Xia Wang ( FJAU 72013, paratype!).

Description: —Basidiomata 20–43 mm high, 10–30 mm wide, and conical in shape. When young surface white (1A1) to grayish yellow (4C5), then changing to yellow white (1A2, 3A2). Upward irregularity dichotomous, the primary branches axil forming “V” shape, then the branching points become gradually rounded upwards and eventually transform into a “U” shape, branches lightly divergent. Internodes slender, diminishing gradually. Apex awl-shaped or dichotomous, dull yellow, grayish yellow or honey yellow (3B4, 3B5, 4C7, 5C6). The stipe is not distinct or up to 20 mm height and 2–5 mm width, constituting up to 1/8 of the total basidioma height, concolourous with branches or paler, cylindrical in shape, tapering downwards, surface smooth and covered with white short tomentum at the base. Context fragile and white. Odour and taste not distinctive. Macrochemical reactions: FCL (FeCl3) test on hymenium negative. Dry basidiomata pale creamy in colour, with slight yellowish tones.

Basidiospores, (60/2/2) (3.8–)3.9–4.7(–4.8) × 3.4–4.1(–4.2) μm, Q=(1.06–)1.07–1.19(–1.23), sub-globose to broadly ellipsoidal and ornamentated with verruculose or nearly wart on the surface, ornamentation are smaller and regular (0.2–0.4 μm), with an big drip, hyaline in KOH, thin-walled. Basidia 20–27(–30) × 5–7(–8) μm, broadly clavate to cylindrical, hyaline, thin-walled, 4-spored, sterigmata 3–5 μm long, base with clamped connections. Cystidia absent. Hymenium 25–33 μm thick. Subhymenium 8–15 μm thick. Tramal hyphae monomitic, hyaline, thin walled, with clamps. Hyphae of branches parallel, cells 2.2–7.9 μm in diameter, rarely inflated up to 16.8 μm, with clamps present. Hyphae of the stem 2–9 μm wide, often containing inflated cells diameter up to 17 μm.

Habitat: —Gregarious or caspitose, 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 (paratype): — CHINA. Jilin Province: Jilin, Huadian City, Hongshi National Forest Park, 16 August 2024, T. Bau & Xianyan Zhou (FJAU72014).

Figures

FIGURE 2. a. Basidiomata of Ramariopsis eburnean (FJAU72012, holotype); b. Basidiomata of Ramariopsis eburnean (FJAU72013, paratype); c. Basidiospores under optical microscope; d. Basidiospores under SEM, 10.00K ×. Scale bars: (a, b=10 mm; c=5 µm; d=1 µm).

FIGURE 3. Illustration of Ramariopsis eburnean a. Basidiomata, b. Basidiospores, c. Basidia, Scale bars: (a=10 mm; b=5 µm; c=8 µm)