Lindsaea heterophylla Dryand.

Rhizome rather to very short-creeping, 1.5-3 mm ø; scales medium brown, very narrowly triangular, to 2.5 mm long, to 7-seriate at base, long-acuminate, the apical uniseriate part rather long. Leaves close; petioles (3-) 10-50 cm long, 0.5-2 times as long as the lamina, stramineous to dark brown, adaxially often paler, abaxially bi-angular, sharply so above, sometimes pale-angled. Lamina simply pinnate to bipinnate or rarely to subtripinnate, narrowly oblong or oblong or, especially if bipinnate, deltoid, (6-) 10-45 cm long, (3-)6-20 cm wide, 2-6 times as long as wide, with 4-25 primary divisions to a side. Primary rachis mostly stramineous, abaxially sharply bi-angular or broadly and shallowly sulcate. Primary pinnae rather remote, the upper ones closer, spreading or, if pinnate, ascending, herbaceous to chartaceous, medium green or olivaceous when dry. Simple primary pinnae lanceolate or elongate-triangular or the smaller ones rhombic, the base unequal, basiscopically narrower, acroscopically in extreme cases cordu-late, the larger ones 2-10 cm long, 0.75-1.5 cm wide, 1.5-8 times as long as wide; larger pinnate primary pinnae 8-18 cm long, (0.75-)1.5-6 cm wide, 2-9 times as long as wide, triangular to linear, with 1-15 pinnules, these 1/2-5 cm long, cuneate-subflabellate to suborbicular or of the same shape as undivided primary pinnae, spreading or somewhat ascending; secondary rachises abaxially subterete to bi-angular, stramineous, or reddish and pale-margined, at least upward green-margined. Upper pinnae of lamina gradually reduced, the upper ones usually rhombic, subacute or obtuse, less often suborbicular or flabellate, usually not less than 0.5 cm long, a few connected with the mostly comparatively large, lanceolate or elongate-triangular, obtuse to acuminate terminal segment; apices of pinnate pinnae similar. Pinnate pinnae, if any, occurring basally in the lamina, but sometimes above pinnae of simpler structure, but not as irregularly arranged as sometimes in L. orbiculata. Transitions between pinnate and simple pinnae usually paucijugate-pinnate with large terminal segment rather than lobed to pinnatifid. Margin of sterile pinnules (very rare in adult plants) crenate-dentate to subentire; fertile margin subentire or mostly +-erose, little sclerotic. Ultimate divisions, if elongate, with a percurrent, distinct, stramineous, abaxially prominulous costa; veins oblique, less so towards the margin, 1-3 times forked, immersed but evident, irregularly anastomosing, forming (except in the bases of large pinnae) an interrupted series of areoles 0.5-1 mm wide (very rarely a second series), or free, but scarcely a leaf without any anastomoses. Sori continuous except as interrupted by the incisions, in pinna-apices sometimes interrupted by serrations, in lobed pinnae often extending close to or around the bottom of the sinus. Indusium pale, entire to erose, 0.3-0.5 mm wide, falling short of the margin by half its width to reaching it, little reflexed at maturity. Spores pale yellowish, trilete, smooth, c. 30 μ (sometimes irregular and apparently abortive, whieh might be connected with hybrid origin).

In open to somewhat shaded, mostly moist places, up to 1100 m, mostly at lower altitude.