台湾双盖蕨 tai wan shuang gai jue

Allantodia kappanensis (Hayata) Ching; A. taiwanensis (Tagawa) Ching; Diplazium taiwanense Tagawa; D. virescens Kunze var. taiwanense (Tagawa) Sa. Kurata.

Plants evergreen, medium-sized. Rhizome ascending to erect, brown, densely scaly at apex; scales black-brown to black, shiny, linear-lanceolate, ca. 1.5 cm, thickly membranous, margin with black, narrow band, toothed, apex filiform; fronds caespitose. Fertile frond up to ca. 1 m; stipe brown at base, upward green-stramineous, 30-45 cm, ca. 6 mm in diam., base densely scaly; scales brown, linear-lanceolate, upward glabrous, grooved adaxially; lamina 2-pinnate with pinnules pinnatifid, deltoid to ovate-deltoid, 50-70 × 40-60 cm, apex acuminate; pinnae ca. 10 pairs, alternate, slightly ascending, with stalk up to 4 cm, 1-pinnate with pinnules pinnatifid; basal pinnae largest, oblong, 25-30 × 15-20 cm, slightly narrowed to base, base truncate, apex acuminate; pinnules 10-12 pairs, alternate, spreading, with stalk ca. 5 mm, lanceolate, ca. 10 × 2 cm, base slightly wider, truncate or broadly cuneate, pinnatilobate to 1/3 from margin, apex long acuminate; pinnule lobes up to 10 pairs, subspreading, oblong, ca. 5 mm wide, margin minutely serrate, apex rounded or subtruncate; veins pinnate, veinlets 4 or 5 pairs, simple, ascending. Lamina dark green when dry, herbaceous, glabrous on both surfaces; rachis green-stramineous, shallowly grooved adaxially, costae and costules abaxially with sparse, linear diamond-shaped, brown, small scales or subglabrous. Sori oblong, short, straight, 1-2 mm, 1 or 2 pairs per lobe, medial; indusia brown, oblong, membranous, opening acroscopically, persistent. Spores hemispherical, perispore with aculeate protuberances on surface.

Broad-leaved forests; below 100-500 m. Taiwan [S Japan].

Diplazium kappanense and D. taiwanense were considered to be different species with forked or simple veinlets; however, here they are treated as conspecific.