3–6 in. broad, oblong to oblong-ovate or oblong-deltoid, erect or drooping, pale-green, very thin and membranous, flaccid, quite glabrous, 3–4-pinnate; rhachis very slender, almost capillary, flexuous, polished. Lower pinnæ 2–4 in. long, ovate-deltoid. Pinnules on rather long and slender petioles, not dimidiate, ¼–⅓ in. long, often broader than long, variable in shape, usually suborbicular with a more or less cuneate base, upper margin broadly and shallowly lobed. Pinnules of barren fronds often larger, entire or obscurely lobed. Sori 2–6 to a pinnule, placed in the notches or sinuses between the lobes. Indusium rather large, reniform or transversely oblong, pale.—Hook. Sp. Fil. ii. 37, t. 77a; Hook. f. Fl Nov. Zel. ii. 21; Handb. N.Z. Fl. 360; Hook. and Bak. Syn. Fil. 123; Benth. Fl. Austral. vii. 724; Thoms. N.Z. Ferns, 54; Field, N.Z. Ferns, 83, t. 17, f. 1. A. assimile, Swartz, Syn. Fil. 125, 322; Raoul, Choix, 38. A. trigonum, Labill. Pl. Nov. Holl. ii. 99, t. 248; Raoul, Choix, 38.
North Island: Plentiful in lowland districts from the North Cape to the Thames and Waikato Rivers, from thence rare and local to Hawke's Bay (Colenso!) and Taranaki (H. C. Field!). South Island: Has been reported from Nelson and Canterbury, but I have seen no specimens.
An abundant fern in most tropical and subtropical countries.
2. A. diaphanum, Blume, Enum. Fil. Jav. 215.—Rhizome very short, tufted; rootlets long, fibrous, densely tomentose, bearing numerous small oblong tubers. Stipes 2–6 in. long, very slender, almost capillary, wiry, glabrous or slightly scaly towards the base, dark purplish-brown or almost black. Fronds 3–6 in. long, rarely more, simply pinnate, or with 1–2 branches at the base which are sometimes almost as long as the central portion but usually much shorter, thin and membranous, flaccid, dark-green; branches ½–1 in. diam. Pinnules numerous, shortly petiolate, ⅓–½ in. long, about ¼ in. deep, dimidiate-oblong; lower margin straight or more or less decurved, entire; upper margin about parallel, and together with the rounded apex deeply crenate-toothed; surfaces sparingly setulose with minute stiff black hairs. Sori 4–8 to a pinnule, rarely more, placed in the notches of the upper and outer margins. Indusium reniform, pale, minutely setulose.—Hook. Sp. Fil. ii. 10 t. 80c; Hook. and Bak. Syn. Fil. 117; Thoms. N.Z. Ferns, 53 Field, N.Z. Ferns, 80, t. 13, f. 5. A. affine, Hook. Sp. Fil. ii. 32; Hook. f. Fl. Nov. Zel. ii. 20; Handb. N.Z. Fl. 360 (not of Willd.). A. setulosum, J. Sm. in. Bot. Mag. Comp. (1846) 22.
Var. polymorphum, Cheesem.—Fronds smaller, pale-green, usually simply pinnate, rarely branched at the base. Surfaces of the pinnæ and indusia quite glabrous.—A. polymorphum, Col. in Trans. N.Z. Inst. xx. (1888) 215. A. tuberosum, Col. I.c. 217.
Kermadec Islands, North Island: Not uncommon in woods at low elevations, usually in rich alluvial soils. South Island: Apparently rare and 31— Fl.
