Tuber verrucosivolvum S.P. Wan, 2017

Wan, Shanping, Xu, Wenjun, Tan, Nianwu, Wang, Yun, Zheng, Yi & Yu, Fuqiang, 2017, Three Excavatum species Tuber badium, T. depressum and T. verrucosivolvum from Sichuan Province, China, Phytotaxa 296 (3), pp. 228-238 : 235-236

Tuber verrucosivolvum S.P. Wan , sp. nov. ( Fig. 5 ).

MycoBank:—MB 818793

Type:— CHINA. Sichuan Province: Huidong County, in soil under forest dominated by P. armandii, Dec. 2012 , wsp060, HKAS 88863.

Ascomata subglobose, 1–1.5 cm in diam., firm, with small basal hole, entire surface covered with distinctly high pyramidal warts, cracked in some areas, yellow to brown; interior cavity surface covered with many fine, irregular scales and large warts, yellow to brown when fresh. Peridium 300–640 μm thick including the 36–185 μm high verrucose warts, pseudoparenchymatous, the outer layer 60–290 μm thick, composed of big, subglobose to subangular cells, 3–23 × 1–13.5 μm, yellow, pale brown or hyaline; the inner layer 70–450 μm thick, composed of intricately interwoven, hyaline and thin-walled hyphae, 1–5 μm in diam. Gleba solid, yellowish brown when mature, marbled with white-yellow veins. Gleba composed of hyaline, interwoven, thin-walled hyphae, 1–6 μm broad at the septa, the cells cylindrical interwoven to inflated, 3.5–27 × 2.5–17.5. Odor pleasant. Taste not recorded. Asci 90–120 × (62–)64– 87 μm, globose to subglobose, pyriform, ellipsoid or irregular, hyaline, sessile or with a short stalk, thin walled 1–2 μm thick, 1–4 spored. Ascospores broadly ellipsoid, ellipsoid, sometimes globose or subglobose, hyaline when young, becoming brown at maturity; excluding their alveolate-reticulate ornamentation, in 1-spored asci (38–)39–55(–58) × (29.5–)31–47 μm, in 2-spored (27–)35–47 × (24–)28–40(–45) μm, in 3-spored 28(–31)–43 × 26–33.5(–36) μm, and in 4-spored (20.5–)30–39(–40) × (20.5–)26–31.5(–32) μm; Q = 1–1.6, Qm = 1.25 ± 0.11; reticulum with 3–5 meshes along the spore length and 2–4 across, the alveolar walls up to 2–9.5 μm tall.

Diagnosis: — Tuber sinoexcavatum differs in its lower peridium (200–300 μm), single type of ascospores (globose) and lower alveolar walls (5 μm). Tuber fulgens differs in its orange-brown ascomata and relatively single type of ascospores (globose to subglobose).

Habit, habitat and distribution: —Hypogeous, in soil under forest dominated by P.armandii in Sichuan Province, China. Only known from China.

Etymology: —In reference to the distinctly verrucose warts of the ascoma.

Other material examined: — CHINA. Sichuan Province: Huidong County, in soil under forest dominated by P. armandii, Dec. 2012 , wsp061, HKAS 88864, collected by S.P. Wan.

Figures

FIGURE 5. Tuber verrucosivolvum (HKAS 88863, holotype).a. Ascoma and sections. b. Surface warts of ascoma. c, d. Peridium sections. e. Light micrograph (LM) of asci and ascospores. f. Scanning electron micrograph of ascospore.