Basidiocarps scattered, dendroid composed of cylindrical dichotomous branches, yellow to orange, white near the base, soft-cartilaginous, 10–30 mm high, 1–2 mm diam. Structure showing in transverse section composed of a central core of compact parallel hyphae surrounded by a zone of loosely interwoven hyphae enclosed by the hymenium. Internal hyphae branched, thin-walled, septate, pale yellow, 2–5 μm diam, without clamp connections. Hymenium amphigenous. Probasidia cylindrical, yellow, 25–37 × 3–5 μm, becoming bifurcate. Basidiospores subglobose to reniform, with an apiculum at the base, thin-walled, pale yellow, 7.5–15 × 3.5–6.5 μm (av. 10 × 4.5 μm; n = 20), 0–1-septate, germination via germ tubes.
Culture characteristics — Colonies attaining about 5 mm diam, velvety to lanose, white-yellow. Conidiogenous cells on vegetative hyphae, polyblastic, sympodial. Conidia subglobose, 5 × 3 μm.
Specimens examined. japan, Nagano, Sugadairakougen, on litter of Abies veitchii Lindl., 10 Aug. 2005, T. Shirouzu, TNS-F-15704 (HNo.175), culture MAFF240119; Saitama, Chichibu, on dead branches of an unknown conifer, 20 July 2006, Y. Takahashi, TNS-F-15705 (HNo.466).
Notes — This species is characterised by hyphae without clamp connections and large, dichotomously branched orange-coloured basidiocarps. In contrast to C. cornea, C. viscosa has been frequently found on woody materials of coniferous trees (McNabb 1965a, Reid 1974). In Japan, this has been also reported from coniferous wood (Kobayasi 1939b).