哀牢山复叶耳蕨 ai lao shan fu ye er jue

Arachniodes jingdongensis Ching.

Rhizome creeping, succulent at growing apex, 2.5-3 cm in diam., densely scaly; scales pale brown, ovate-lanceolate, ca. 8 × 3 mm. Fronds remote, 0.9-1.2 m; stipe stramineous or purplish below, 50-55 cm, 3-5 mm in diam., base scaly as rhizome but fugacious, upward glabrescent; lamina 3-pinnate, pale greenish when dried, ovate-deltoid, 45-68 × 30-45 cm, subleathery and firm, base rounded-cuneate, apex acuminate, rachis glabrescent; pinnae 10-15 pairs, alternate, with 1.5-2 cm stalk, obliquely spreading, approximate or imbricate; lowest pair ovate-oblong, 29-35 × 14-15 cm, base cuneate, apex acuminate; primary pinnules 15-20 pairs, with ca. 1 cm stalk, obliquely spreading, contiguous, lanceolate, (proximal pairs 12-13 × 4-4.5 cm), base rounded-cuneate, apex acuminate; secondary pinnules 12-14 pairs, subsessile, spreading, contiguous, obliquely rhombic, 2-2.5 × ca. 1 cm, base acroscopically slightly auriculate, apex acute, acroscopic margin pinnatifid; lobes obtuse, apex mucronate, margin often serrate with mucronate teeth; upper pinnae gradually reduced; axes of lamina, pinna, and pinnule (and veins as well) sometimes retaining a few minute dark brown subulate scales abaxially. Sori large, terminal on veinlets, 4-7 pairs per ultimate pinnule, medial between midvein and margin; indusia dark brown, firmly membranous, and entire.

● Evergreen broad-leaved forests; 2400-2500 m. Yunnan (Ailao Shan).

This fern is very closely related to Arachniodes nipponica, and it also is similar to A. tomitae Sa. Kurata in appearance.