林下凸轴蕨 lin xia tu zhou jue

Dryopteris hattorii H. Itô, Bot. Mag. (Tokyo) 99: 359. 1935 ["hattori"]; D. laxa (Franchet & Savatier) C. Christensen var. dilatata Koidzumi; Lastrea hattorii (H. Itô) Tagawa; L. laxa (Franchet & Savatier) Copeland var. dilatata (Koidzumi) Honda; Thelypteris hattorii (H. Itô) Tagawa; T. nemoralis Ching.

Plants 30-60 cm tall. Rhizomes short, decumbent, apices including stipe bases densely covered with reddish brown lanceolate scales and grayish white setae. Fronds approximate; stipes 15-30 cm, bases dark brown, stramineous above bases, subglabrous; laminae ovate-triangular, 15-35 × 14-26 cm, broadest at bases, bases rounded-truncate, 3-pinnate-pinnatifid, apices acuminate and pinnatifid; pinnae 12-16 pairs, proximal ones subopposite, distal ones alternate, sessile, or proximal pinnae sometimes with 0.5-1 mm stalks; proximal pair not shortened, of similar shape and size as distal ones, lanceolate, 10-15 × 2.5-3.5 cm, pinnae not tapering to base except for proximal 2 pairs, rounded-truncate at bases, pinnate-pinnatifid, acuminate at apices; pinnules ca. 16 pairs, subopposite, pinnae distal to middle ones connected to each other by narrow wings, proximal ones oblong-lanceolate, 2.5-3 × ca. 1 cm, bases decurrent, sessile, separated from each other, pinnatifid to ca. 2/3, apices rounded-obtuse or acute; segments oblong, 3.5-4 × ca. 2.4 mm, entire, rounded-obtuse at apices. Veins not evident, lateral veins simple or forked, 2 or 3 pairs per segment, not reaching margins. Laminae herbaceous, when dry green, densely grayish white pubescent on both surfaces. Sori small, orbicular, usually 1 per segment, attached near ends of acroscopic veinlets on bases and close to margins; indusia small, orbicular-reniform, membranous, when dry grayish brown, sparsely pubescent, persistent.

Valley forests; 100-1700 m. S Anhui, N Fujian, N Guangxi, Hunan, Jiangxi, SW Sichuan, Zhejiang [Japan].