5. Parathelypteris borealis (H. Hara) K. H. Shing, Fl. Reipubl. Popularis Sin. 4(1): 37. 1999.
狭脚金星蕨 xia jiao jin xing jue
Dryopteris nipponica (Franchet & Savatier) C. Christensen var. borealis H. Hara, Bot. Mag. (Tokyo) 48: 695. 1934; Parathelypteris nipponica (Franchet & Savatier) Ching var. borealis (H. Hara) Nakaike; Thelypteris nipponica (Franchet & Savatier) Ching var. borealis (H. Hara) H. Hara.
Plants 45-65 cm tall. Rhizomes long creeping, with dense rusty yellow hairs. Fronds approximate; stipes ca. 13 cm, stramineous, glabrous, bases with sparse brown ovate scales; laminae 25-50 × 5-11 cm; pinnae alternate, flatly spreading, sessile, proximal 7 or 8 pairs abruptly tapering into auricles, lowest ones tuberculate; middle pinnae lanceolate, 3-6 × 0.6-0.9 cm, bases slightly broadened, symmetrical, subtruncate, pinnatifid nearly to costae, apices acuminate; segments 12-18 pairs, oblong, 3-4.5 × 1.5-2 mm, entire, obtuse at apices. Veinlets evident, simple, 4 or 5 pairs per segment, proximal pairs arising from above bases of costules. Laminae herbaceous, yellowish dark green when dry, with dense orange-yellow spherical glands abaxially, with sparse grayish white fine acicular hairs along costae, costules, and margins, adaxially along grooves of costae with short hairs, elsewhere glabrous. Sori orbicular, dorsifixed near ends of veinlets and close to margins, 1-4 pairs per segment; indusia small, orbicular-reniform, brown, membranous, subglabrous. Spores bilateral, orbicular-reniform, perispores few corrugate and finely reticulate on corrugations.
Valley thickets, wet shaded places in forests, common; 400-1900 m. N Anhui, N Fujian, Guangxi, Guizhou, Hunan, Jiangxi, Shaanxi, Sichuan [Japan].
Parathelypteris borealis is very similar to P. nipponica in laminar outline but differs by laminae with dense orange yellow spherical glands abaxially and indusia subglabrous. It is also similar to P. qinlingensis, but the latter has rhizomes ascending, costae with denser long acicular hairs abaxially, and indusia with more setae.