53. Athyrium costulalisorum Ching, Acta Bot. Boreal.-Occid. Sin. 6(1): 15. 1986.
川西蹄盖蕨 chuan xi ti gai jue
Rhizomes erect, apex densely clothed with brown, narrowly lanceolate scales. Fronds caespitose; fertile fronds up to 1.2 m; stipe blackish brown at base, upward brown-stramineous, shiny, ca. 40 cm, base ca. 5 mm in diam., similarly scaly, upward glabrate; lamina 2-pinnate, ovate-oblong, 50-60 × 18-20 cm, base narrowly cuneate, apex acuminate; pinnae more than 20 pairs, alternate, lower pinnae strongly ascending, upper pinnae ascending, subsessile or shortly stalked (stalk ca. 2 mm); basal pinnae larger, linear-lanceolate, up to 27 × ca. 5 cm at middle, base narrowed, pinnate, apex caudate-acuminate; second basal and upper pinnae similar to basal pinnae but gradually shortened, but not narrowed or broader at base; pinnules ca. 28 pairs, alternate, spreading or subspreading, lower pinnules gradually shortened, basal pinnules ca. 1.2 cm; middle pinnules broadly lanceolate, 2.4-3 cm × 9-12 mm at base, base broadened, subequilateral, broadly cuneate, subsessile, pinnatipartite to 3/4 to costule, apex shortly acuminate; pinnule segments 8-10 pairs, slightly oblique, approximate, oblong, 2.5-3 × ca. 2 mm, margin entire or sparsely serrulate, apex obtuse-rounded, with 3-6 triangular teeth; veins visible on both surfaces, pinnate in segments, lateral veins 2 or 3 pairs, oblique, simple. Lamina thickly papery when dried, grass-green, glabrate on both surfaces; rachis and costae abaxially stramineous, slightly pale purplish red, glabrate, with subulate spines on adaxial side at base of costa or costule, midribs of pinnules also with subulate short spines. Sori elliptic, orbicular-reniform, J-shaped, or horseshoe-shaped, 1 per segment, 2-4 in basal segment, subcostular; indusia orange-brown, elliptic, orbicular-reniform, J-shaped, or horseshoe-shaped, membranous, somewhat erose at margin, persistent. Perispore surface without folds.
● Grassy mountain slopes; ca. 2800 m. W Sichuan (Baoxing).