Calostoma areolatum Y.H. Ma, B. Zhang & Y. Li, Sydowia, 2018

Xu, Chang, Liang, Zhi-Qun, Jiang, Shuai, Zhang, Ping, Huang, Sheng-Zhuo & Zeng, Nian- Kai, 2022, Notes on two species of Calostoma (Calostomataceae, Boletales) from the south of China, Phytotaxa 533 (1), pp. 49-61 : 54-55

Calostoma areolatum Y.H. Ma, B. Zhang & Y. Li, Sydowia 70: 230, 2018 ( Figs. 2a–c , 3 , 5a–c )

Description:— Basidiomata stalked. Peridium subglobose or globose, 1.4–1.5 cm in diam. Exoperidium composed of many, dark brown (2E3), cone-shaped or pyramid-shaped warts or appendages of varying sizes, which occasionally fall off with age. Mesoperidium absent. Endoperidium brown (3E5), with many polygonal grids on the surface when mature. Ostiolum star-shaped, teeth 4–6, yellow (4A5) when young, vermilion (9B7) when mature, exposing a white spore bag. Spore-sac yellowish (1A2), membranous, 0.5 cm in diam, with yellowish (1A2) power, connected to the ostiolum. Stipe strongly developed, central, 2.5–4 × 1.2 cm; surface gelatinous, dark brown (4E7), composed of many regularly arranged and occasional branching longitudinal cords.

Basidiospores [360/18/6] (13.5–)14–20(–20.5) × (14–)14.5–20 μm, Q = (0.93–)0.94–1.05(–1.06), Qm = 1.00 ± 0.03 (including ornamentation), [360/18/6] (7–)8.5–12 × (7–)8.5–12 μm, Q = (0.92–)0.94–1.05(–1.09), Qm = 1.00 ± 0.03 (excluding ornamentation), globose, petal-like under light microscope, petals consist of many vertical lines under SEM, hyaline to pale yellow in KOH. Basidia not seen. Exoperidium hyphae sparsely branched, gelatinized, pale yellow in KOH; terminal cells 31–68 × 12–16 μm, slightly thick-walled (0.2–0.4 μm). Endoperidium hyphae hyaline to yellowish in KOH, occasionally branched; terminal cells 23–110 × 3–4 μm, thick-walled (1–3 μm). Stipe hyphae composed of two layers; hyphae in the first layer pale yellow, with terminal cells measuring14–50 × 4–10 μm, thick-walled (2–5 μm); hyphae in the second layer hyaline, with terminal cells measuring 10–99 × 3–4.5 μm, slightly thick-walled (0.4 μm), occasionally with hyaline granular appendages. Clamp connections occasionally observed in endoperidium hyphae.

Habitat:—Gregarious or scattered on yellow soil (pH4.8) in forests dominated by Lithocarpus spp .

Known distribution:— Fujian, Jiangxi ( Liu et al. 2018) and Hainan Provinces of China.

Specimens examined:— CHINA. Hainan Province: Limushan of Hainan Tropical Rainforest National Park , elev. 750 m, 27 July 2017, N. K . Zeng 3128, 3132, 3135, 3137 ( FHMU2089 , 2093 , 2096 , 2098 ); Yinggeling of Hainan Tropical Rainforest National Park , elev. 800 m, 26 June 2013, N. K . Zeng1199 ( FHMU765 ) .

Figures

FIGURE 2. Basidiomata of Calostoma species. a–c Calostoma areolatum (a from FHMU765; b from FHMU2098; c from FHMU2093); d–f Calostoma sinocinnabarinum (d from FHMU1007; e from FHMU3739, holotype; f from FHMU3818). a–e photos by N.K. Zeng; f photo by S.Z. Huang.

FIGURE 3. Microscopic features of C. areolatum (FHMU2089). a. Basidiospores. b. Exoperidium hyphae. c. Endoperidium hyphae. d. First layer of stipe hyphae. e. Second layer of stipe hyphae. Bars = 10 μm. Drawings by C. Xu.

FIGURE 5. Basidiosporesof Calostoma species fromdry materials underSEM.a–c. C.areolatum (FHMU2089).d–f. C.sinocinnabarinum (FHMU3739, holotype). Bars = 5 μm.