CHINA. Guangxi Province, Hechi city, Luocheng county, Pingying village, Jiuwan Mountain National Nature Reserve, 108°48'E, 25°19'N, G.J. Li, H.S. Ma, Z.L. Lin & M.Z. Zhang, 7 August 2017, GX20172598 (HMAS 279589).

Cheejenii was named in honor of Chee-Jen Chen for his contributions to systematics of tremellalean fungi.

Basidiomata sessile, cerebriform, up to 1.0–3.0 cm in diameter, broadly attached to substratum, soft gelatinous, pale white when fresh and pale brown in dry condition. Hyphae smooth, thick-walled, slender, 2.0–4.5 μm in diameter, often anastomosing, clamp connections abundant, loop-like forming a large hollow. Haustoria rare, small, subglobose, ca 2.0 μm in diameter, with a single hypha. Hyphidia abundant, smooth, thin-walled, 2.5–4.0 μm in diameter, branched, hyphidia and basidia derived from the same hypha. Probasidial initials subglobose, ovoid or pyriform. Mature basidia subglobose, broadly ellipsoid or ovoid, mostly two-celled, and occasionally four-celled, with apical protuberance, often longitudinally septate or occasionally oblique or cruciate-septate, thin-walled, 12.0–17.0 μm × 13.0–18.0 μm, stalked, 2.0–4.0 μm long, with sterigmata up to 70 μm, not swollen at apex. Basidiospores hyaline, smooth, thin-walled, subglobose to broadly ellipsoid, apiculate, 5.0–10.0 μm × 4.5–8.0 μm, L = 8.6 ± 1.1 μm, W = 6.6 ± 0.8 μm, Q = 1.1–1.8 (n = 40). Basidiospores forming secondary ballistoconidia by the formation of a sterigma. Conidia ellipsoid, smooth, hyaline, thin-walled, 2.2–4.0 μm × 1.8–3.0 μm, L = 3.1 ± 0.6 μm, W = 2.2 ± 0.3 μm, Q = 1.0–2.0 (n = 40), monokaryotic, budding from apex of sterigmata.

On wood of deciduous tree, in forest dominated by Fagaceae, Lauraceae, Theaceae, Magnoliaceae, and Hamamelidaceae.

CHINA. Guangxi Province, Hechi city, Luocheng county, Pingying village, Jiuwan Mountain National Nature Reserve, 108°48'E, 25°19'N, G.J. Li, H.S. Ma, Z.L. Lin & M.Z. Zhang, 7 August 2017, GX20172640 (HMAS 279590).

Two specimens form the sister group to T.fibulifera, T.lloydiae-candidae, and T.resupinata and represent a new species, T.cheejenii. The sequence identities between T.cheejenii and T.fibulifera are 95.7%–95.9% and 92.5%–93.2% in the D1/D2 domain and ITS region, respectively. Similarly, T.cheejenii and T.lloydiae-candidae showed 96.1%–96.2% and 92.1% sequence identities in the D1/D2 domain and ITS region, respectively. Tremellacheejenii and T.resupinata showed 90.4% and 89.9% sequence identities in the D1/D2 domain and ITS region, respectively. Tremellacheejenii is distinct from T.fibulifera in its bigger basidia (12.0–17.0 μm × 13.0–18.0 μm in T.cheejenii vs 14–16 μm × 10–13 μm in T.fibulifera). However, the basidia of T.cheejenii are smaller than that of T.resupinata (12.0–17.0 μm × 13.0–18.0 μm in T.cheejenii vs 27.0–40.0 μm × 22.0–31.0 μm in T.resupinata) (Chen 1998; Malysheva et al. 2015). Moreover, conidia are produced from the sterigmata in T.cheejenii compared to the absence of conidia in T.fibulifera, T.lloydiae-candidae, and T.resupinata.