Tuber melanorufum L. Fan, 2023

Fu, Hao-Yu & Fan, Li, 2023, Tuber melanorufum and T. tomentellum, two new truffle species from China, Phytotaxa 594 (3), pp. 178-190 : 182-186

Tuber melanorufum L. Fan sp. nov.

( FIG. 2 )

MycoBank:—MB 846497

Diagnosis:—differed from other species by the large red-brown to blackish ascomata covered with distinctively fine warts and the ascospores ornamented with crowded spine-reticulations.

Etymology:— melano, latin, means black; rufum , latin, means red. Referring to the color of ascomata that are red-brown when young and change to blackish to black with age.

Typification:— CHINA. Yunnan Province: Huize County, in soil under a Pinus forest, 31 Oct 2020, collected by Jinzhong Cao ( BJTC FAN1273 ) .

Description:— Ascomata 1.6–4.5 cm diam, irregularly globose to subglobose, reddish (#f18f5f) to red brown (#800000) when young, then changing blackish to black (#460707) with age, surface covered with distinctly fine warts, often with some superficial and pale colored furrows. Odor light, favour not recorded. Gleba pale when young, brown (#4e0000) to coffee brown (#670000) at maturity, but never black, marbled with narrow and numerous whitish veins.

Peridium 350–400 μm thick, two-layered: outer layer 200–250 μm thick including warts of 30–50 μm high, pseudoparenchymatous, composed of subglobose to irregularly shaped cells of 5–15 × 5–20 μm wide, with slightly thickened walls, brown walls at outermost cells; inner layer 150–200 μm thick, composed of interwoven hyphae 2.5– 7.5 μm wide, hyaline thin-walled. Asci subglobose or ovoid, 65–75 × 55–62.5 μm, hyaline, thick-walled of 2.5–3μm, 1–4(–5)-spored, sessile or with a short stalk at maturity. Ascospores ellipsoid to oblong-ellipsoid, usually narrowed in one end, yellow brownish (#a36e12) at maturity, ornamented with densely spine-reticulations of 2.3–3(–5) μm high, negative in Melzer’s reagent, excluding ornamentation, in 1-spored asci 25–57.8 × 15–28.5 μm, Q = 1.24–2.57 (Qm =1.91 ± 0.66) (n = 30), in 2-spored asci 26–51 × 13.6–25.6μm, Q = 1.41–2.62 (Qm =2.02 ± 0.6) (n = 30), in 3-spored asci 22.1–43.9 × 13.3–23.2 μm, Q = 1.18–2.31 (Qm = 1.75 ± 0.56) (n = 30), in 4(–5)-spored asci 17.9–40 × 11.7–21.2 μm, Q = 1–2.45 (Qm = 1.73 ± 0.73) (n = 30).

Habit, habitat and distribution: —hypogeous, gregarious, in soil under Pinus forest in Yunnan province, China. Currently known only from China.

Specimens examined. CHINA. Yunnan Province: Huize County, in soil under forest of Pinus sp. , 21 Oct 2020, collected by Jinzhong Cao ( BITC FAN1274 , BJTC 1276 , BJTC FAN1287 ) .

Figures

FIGURE 2. Tuber melanorufum. a. Ascomata (BJTC FAN1273, holotype). b. SEM of ascospore. c, d, e. Light micrographs of asci and ascospores. Scale bars: a = 1 cm, b = 5 μm, c = 20 μm, d, e = 50 μm. Photos by: Li Fan.