薄叶凸轴蕨 bao ye tu zhou jue

Aspidium flaccidum Blume, Enum. Pl. Javae 2: 161. 1828; Dryopteris flaccida (Blume) Kuntze; D. gracilescens (Blume) Kuntze var. decipiens (C. B. Clarke) Alderwerelt; Lastrea flaccida (Blume) T. Moore; L. gracilescens Hooker var. decipiens (C. B. Clarke) Beddome; Metathelypteris decipiens (C. B. Clarke) Ching; Nephrodium flaccidum (Blume) Hooker; N. gracilescens (Blume) Hooker var. decipiens C. B. Clarke; Thelypteris decipiens (C. B. Clarke) Ching; T. flaccida (Blume) Ching.

Plants 40-60 cm tall. Rhizomes thick and short, erect, with deep brown linear-lanceolate scales. Fronds clustered; stipes 15-30 cm, bases dark brown, with similar scales and grayish white short acicular hairs, distally stramineous and sparsely shortly hairy; laminae oblong-lanceolate, 25-40 × 12-16 cm, nearly tapering to bases, 2-pinnate-pinnatifid, apices acuminate and pinnatifid; pinnae 10-15 pairs, spreading, subopposite, sessile; proximal ones lanceolate, 7-9 × 2-2.5 cm, bases ± tapering, rounded-truncate, pinnate-pinnatifid, apices caudate-acuminate; pinnules 10-15 pairs, spreading, lanceolate, 1-1.5 × 0.3-0.5 cm, bases decurrent to form narrow wing along costae, pinnatifid to 1/2-2/3 distance to costae, apices rounded-obtuse; segments 5-7 pairs, triangular-lanceolate, 1-2 × ca. 1 mm, entire, obtuse-pointed at apices. Veins not evident, lateral veins simple or forked, 2 or 3 pairs per segment, proximal pair arising from base of costules, not reaching margins. Laminae thinly herbaceous, when dry yellowish green, with dense spreading multicellular acicular hairs on both surfaces. Sori small, orbicular, 1 per segment, attached above middle of acroscopic vein of forked lateral veins; indusia small, orbicular-reniform, membranous, greenish, when dry grayish brown, glabrous or occasionally with few acicular hairs along margins, persistent. 2n = 140.

Streamsides in forests; 700-1800 m. Guizhou, SW Yunnan [Bhutan, India, Indonesia, Malaysia, Nepal, Philippines, Sri Lanka, Thailand, N Vietnam].