镇康膜叶铁角蕨 zhen kang mo ye tie jiao jue

Basionym: Asplenium quercicola Ching, Acta Phytotax. Sin. 10: 188. 1965.

Plants 20-35 cm tall. Rhizome long creeping, 1.5-2.5 mm in diam., apex scaly; scales dark brown to blackish, narrowly triangular to triangular. Fronds remote, up to 12 mm apart, green to brownish dark green when dry, herbaceous, subglabrous; stipe shiny, castaneous-purple, 7-14 cm, base with scales similar to those on rhizome, or subglabrous; lamina 1-pinnate, narrowly oblong-triangular, 15-22 × 3-5 cm, base truncate and slightly reduced, apex acuminate to caudate; rachis shiny, purple to castaneous-purple, pinnae 15-20 pairs, almost sessile and color of rachis not entering base of stipicel abaxially, trapeziform, middle pinnae 1.5-2.5 × 0.7-1 cm, dimidiate, apex truncate to obtuse, base asymmetrical, acroscopic side truncate and parallel to rachis, basiscopic side cut away and narrowly cuneate and entire, acroscopic margin crenate-serrate with retuse teeth, pinnae spreading, basal pinnae slightly reduced and deflexed. Veins distinct, forking and free, each vein ending below a relatively shallow marginal notch, basiscopic side with 3 veins lacking. Sori medial, linear, 3-4 mm; indusia persistent, brown, semi-elliptic, membranous, entire, opening toward costa.

● Epiphytic on Quercus trees; 2400-2700 m. Yunnan.

Hymenasplenium quercicola is most similar to H. szechuanense from which it differs in its more castaneous-purple stipe, more spreading pinnae, and more medial sori. Several sporangia of the type have an orange color and appear collapsed or not fully developed, typical features of hybrids in this family. Due to confusion with similar species, the relationships and the distribution of this taxon are not well known.