First person to use this name on MO: Image Sharer
Etymology: Latin aurantiactus, referring to the orange-colored pileus.
Pileus 0.6–3.0 cm diam, flat, slightly concave at centre, silky, surface orange chrome, margin sometimes flexuous. Lamellae decurrent, broad 0.2–0.3 cm, light orange-yellow, crowded, with lamellulae of two or four lengths, but not intervening, edge entire. Stipe 1.5–3.0 cm long × 0.2–0.3 cm diam, central, cylindrical, surface light orange-yellow, with white fibrils at the base. Pileus context up to 0.2–0.3 cm thick near stipe attachment, thin at margin, concolorous with pileus. Odor faint. Spore deposit white.
Basidiospores 2.0–3.4 × 1.9–3.2 μm, Q = 1.20, subglobose, hyaline, ina- myloid, surface smooth under scanning electron micro- scope. Basidia 12–16 × 3.0–5.5 μm, clavate, four sterigmate, subhyaline, siderophilous granules present in acetocarmine and FeSO4. Hymenial cystidia absent. Hymenophoral trama 110–140 μm broad, regular with thin-walled hyphae 2.0–5.0 μm diam, hyphae not pigmen- ted, subhymenial layer 18–22 μm broad. Pileipellis an epi- cutis of dense radially parallel, repent hyphae, hyphae 2.5– 5.0 μm diam, smooth, thin-walled, pigmented. Stipitipellis hyphae 3.0–9.8 μm diam, smooth, thin-walled, pigmented. Clamp connections present.
Habitat and distribution: Saprophytic in small groups on soil in hardwood-conifer forest. Known from northeastern China.
Additional specimen examined: CHINA. LIAONING PROVINCE: Shenyang City, near the Bird island Park, on soil, 20 Jul 2013, YXD no. 670 (SYAU-FUNGI-005).
Comments: The sporocarp of Calocybe aurantiaca is orange chrome, the basidiospores are small and smooth, and the epicutis is not cellular. These characters support that the new species should be classified in Sect. Carneoviolaceae (Singer 1986). Several species of the section also have a yellow pileus, including C. alpestris (Britzelm.) Singer, C. carnea, and C. coniceps Singer. The gills of these three species are white. Furthermore, C. coniceps has larger basidiospores (6.5–8.5 × 4.5–5.8 μm; Singer 1978) and the gills of C. carnea are adnexed (Fries 1821), which differs from C. aurantiaca, which has decurrent and yellow gills. In the ITS, 28S sequence, and com- bined gene analyses, C. aurantiaca grouped with C. chrysenteron and C. pseudoflammula (Clade III, FIGS. 1– 3). However, the latter two have larger basidiocarps than C. aurantiaca (2.5–5 cm for C. pseudoflammula [Lange 1933] and 1.2–4 cm for C. chrysenteron [Arnolds 2006]). In addition C. chrysenteron has a cellular epicutis, which is absent in C. aurantiaca (Singer 1986).
- Three new species of Calocybe (Agaricales, Basidiomycota) from northeastern China are supported by morphological and molecular data. Jia-Jia Li, Shuang-Yan Wu, Xiao-Dan Yu, Shao-Bin Zhang & Dong-Xu Cao. Pages 55-63 |