4. Thuidium erosifolium S.-Y. Zeng 嗤蚀叶羽藓 chi-shi-ye yu xian
Guihaia 10: 105. pl. 1. 1990. Type. China: Xizang, Lin-zhi Co., Y.-G. Su 2362 (holotype HKAS; isotype PE).
Plants delicate, medium-sized, 3–4 cm long, yellowish brown, lightly brownish when old. Stems often slightly flexuous, irregularly pinnately branched; branches 0.5–1.0 cm long; paraphyllia usually consisting of 3 single cells. Stem leaves ovate-lanceolate at base, tapering to an acuminate apex; margins coarsely serrate, one cell long, more distinct near leaf apex; costa yellowish, stout, vanishing at leaf apex; median leaf cells hexagonal to polygonal, ca. 10 µm wide, thin-walled, centrally unipapillose; branch leaves ovate, with a shortly lanceolate apex, about 1/2 the length of stem leaves. Sporophytes not seen.