紫云山复叶耳蕨 zi yun shan fu ye er jue

Arachniodes pseudosimplicior Ching; A. shuangbaiensis Ching; A. yunqiensis Y. T. Hsieh.

Rhizome shortly creeping, stiff, apex densely scaly; scales (reddish or dark) brown, linear-lanceolate or subulate, ca. 8 × 0.5-1.5 mm, base often remotely fimbriate, apex hairlike, firmly membranous. Fronds approximate, 0.9-1.3 m; stipe stramineous (or blackish brown near base), 50-70 cm, 3-4 mm in diam., lower parts with scales similar to those on rhizome, scales sparser upward; lamina 4-pinnate, greenish when dried, shiny on adaxial surface, ovate-oblong, 40-60 × 30-45 cm, papery, base rounded-cuneate, apex abruptly narrowed and forming a stalked conform terminal pinna, rachis glabrescent; lateral pinnae 5-7 pairs, alternate or lower 1(-3) pairs opposite, with to 3 cm stalk, obliquely spreading; lowest pinnae ovate-deltoid, ca. 30 × 25 cm, base cordate, rounded, or cuneate, apex abruptly narrowed and caudate; primary pinnules ca. 20 pairs, proximal 2(or 3) pairs elongated, deltoid-lanceolate, to 20 × 4 cm, base broadly cuneate or rounded, apex acuminate; secondary pinnules ca. 16 pairs, with to 0.5 cm stalk, linear-lanceolate or oblong (proximal basiscopic ones (or both sides) elongated to 4.5 × 1.5 cm), base cuneate, apex acute; tertiary pinnules shortly stalked or sessile, oblong or falcate, 1-3 × 0.5-1 cm, base acroscopically truncate, basiscopically cuneate, apex acute, margin sharply serrate or pinnatifid, aristate; upper 2 or 3 pairs of pinnae with proximal 1(or 2) pairs of pinnules elongated, other pinnae shortened and linear-lanceolate; axes and veins of ultimate segments with sparse minute brown subulate scales abaxially. Sori terminal on veinlets, 1-6 pairs per ultimate segment, medial between midvein and margin or closer to margin; indusia brown, membranous, and entire.

● Along gullies in broad-leaved forests or by streams on shaded slopes; 400-1800(-2300) m. Chongqing, Guizhou, Hunan, Yunnan, Zhejiang.

This fern differs from its closest affinity Arachniodes simplicior in its larger size and additional order of dissection of the lowest pinna; however, its immature fronds are inseparable from the latter.