海南蹄盖蕨 hai nan ti gai jue

Rhizomes ascending, apex densely clothed with dark brown, linear-lanceolate scales. Fronds caespitose; fertile fronds (30-)40-50 cm; stipe blackish brown at base, upward stramineous, 25-30 cm, ca. 3.5 mm in diam., base similarly scaly, slightly swollen, but not sharpened toward very base, upward glabrate; lamina 2-pinnate, deltoid-ovate, 16-24 × 12-20 cm at base, base almost not narrowed, rounded-truncate, apex abruptly narrowed; pinnae under abruptly narrowed apex 6 or 7 pairs, opposite or subopposite, slightly ascending, with short stalk ca. 1.5 mm or sessile; basal pinnae slightly shortened, oblong-lanceolate, up to 13 × ca. 4.5 cm, base abruptly narrowed, pinnate, apex acuminate; pinnules ca. 14 pairs, basal pinnae subopposite, upper pinnae alternate, spreading, approximate; basal 1 or 2 pairs of pinnules free, others adnate to costa; basal third to fifth basiscopic pinnules longest, oblong-lanceolate, ca. 2.8 cm × 8 mm at middle, pinnatilobate, apex acute or obtuse-rounded; pinnule segments toothed at margin, acroscopic pinnules slightly shorter, narrowly oblong, ca. 1.5 cm × 5 mm at middle, apex obtuse-rounded; second basal pinnae slightly longer than basal pinnae; third basal pinnae subequal to basal pinnae, but broader, not narrowed at base; veins inconspicuous adaxially, visible abaxially, pinnate in pinnules, lateral veins 10-13 pairs, basal veins forked, upper veins simple, but pinnate in basal acroscopic pinnule segments. Lamina thickly papery when dried, brown-green, glabrate on both surfaces; rachis and costae abaxially brown-stramineous, with dense brownish short glandular hairs. Sori oblong, on basal acroscopic veins, only 1 per segment, biseriate on both sides of midrib, single, occasionally double, inframedial; indusia brown, similar to sori in shape, membranous, entire, persistent. Perispore surface without folds, with granular ornamentation.

● Forests on mountain slopes; 1500-1800 m. Hainan (Wuzhi Shan).