中越复叶耳蕨 zhong yue fu ye er jue

Rumohra tonkinensis Ching, Sinensia 5: 52. 1934; Arachniodes obtusipinnula Ching & Y. T. Hsieh; A. subamoena Ching; R. callipteris C. Christensen.

Rhizome ascending, stiff, apex scaly; scales castaneous and lustrous, ovate-lanceolate, 5-9(-15) × 2-3 mm, thinly papery and spreading. Fronds approximate, 60-95 cm; stipe stramineous, 30-50 cm, ca. 4 mm in diam., base with scales similar to those on rhizome, distally glabrescent and glossy; lamina 3- or 4-pinnate, brownish when dried, deltoid-ovate or ovate-pentagonal, 30-55 × 25-30 cm, papery, base rounded or slightly hastate, apex caudate-acuminate, rachis glabrescent and glossy; pinnae 3-5 pairs, alternate, with 1-4 cm stalk, obliquely spreading; lowest pinnae deltoid, 15-22 × 12-17 cm, base rounded or cordate, apex caudate-acuminate; primary pinnules 15-20 pairs, basal pair enlarged, with ca. 1 cm stalk and usually proximal pair of secondary pinnules pinnate, distally abruptly shortened, shortly stalked; secondary (and tertiary) pinnules sessile, rhombic-oblong, 1-1.5 × 0.5-0.9 cm, base obliquely cuneate, apex obtuse, acroscopic margin deeply pinnatifid, lobes with 3-5 sharp teeth; upper 1(or 2) pairs of pinnae with proximal pair of pinnules elongated, upward triangular-lanceolate; veins with sparse minute brown lanceolate scales abaxially. Sori terminal on veinlets, 1-3 pairs per ultimate segment; indusia brown, firmly membranous, entire, fugacious.

Broad-leaved or mixed forests; 1200-1700 m. W Hunan, S Yunnan [Vietnam].