鲜绿凸轴蕨 xian lü tu zhou jue

Nephrodium singalanense Baker, J. Bot. 18: 212. 1880; Dryopteris media Alderwerelt; D. singalanensis (Baker) C. Christensen; Lastrea singalanensis (Baker) Beddome; Thelypteris singalanensis (Baker) Ching.

Plants 75-95 cm tall. Rhizomes thick and short, erect, apices including stipe bases with dense scales; scales brown, linear-lanceolate, caudate at apices. Fronds clustered; stipes 30-50 cm, stramineous, glabrous above bases, polished; laminae lanceolate to broadly lanceolate, 30-70 × 20-30 cm, bases ± tapering, rounded-truncate, pinnate-pinnatifid, apices acuminate and pinnatifid; pinnae 15-25 pairs, spreading or oblique distally, sessile, proximal pair usually slightly shortened, distal ones linear-lanceolate, sometimes falcate, 12-18 × 2-3.5 cm, bases subtruncate, pinnatifid nearly to costae, apices caudate-acuminate; segments 20-30 pairs, basiscopic ones on costae longer than acroscopic ones, oblong, 8-15 × 3-5 mm, entire or serrate along margins, apices blunt-pointed. Veinlets evident, simple or forked on proximal segments, 6-10(-12) pairs, not reaching margins. Laminae papery, when dry green or yellowish green, glabrous abaxially, or sometimes with sparse short acicular hairs along costae and costules, adaxially with grayish white short acicular hairs along rachises and costae. Sori small, glandular, attached on ends of lateral veins or middle of acroscopic vein on forked lateral veins; indusia small, orbicular-reniform, membranous, when dry brownish yellow, sometimes sinuate along margins, glabrous or sparsely capitate shortly hairy. 2n = 144.

Streamsides in forests; 800-1000 m. SE Hainan [Indonesia, Malaysia, Thailand].