ment near the base of the pinnæ on their upper margin and hence supra-axillary, rarely more than one to a pinna. Indusium sub-orbicular, compressed, its base slightly immersed in the segment, deeply 2-valved; valves thin, smooth on the back; margins conspicuously spinulose-dentate.—A. Rich. Fl. Nouv. Zel. 91; A. Cunn. Precur. n. 243; Raoul, Choix, 39; Hook. Syn. Fil. i. 95; Hook. f. Fl. Nov. Zel. ii. 11; Handb. N.Z. Fl. 352; Hook. and Bak. Syn. Fil. 67; Thoms. N.Z. Ferns, 35; Field, N.Z. Ferns, 65, t. 14, f. 7. H. pusillum, Col. in Trans. N.Z. Inst. xii. (1880) 365; (?)H. pygmæum, Col. I.c. xiii. (1881) 376. H. zeelandicum, Van der Bosch.
Var. cupressiforme, Hook. f. Fl. Nov. Zel. ii. 11.—Fronds taller and narrower, more erect, 1–4 in. high. Pinnæ distant; segments more rigid, narrower, often decurved. Sori free, almost, stipitate.—H. cupressiforme, Labill. Pt. Nov. Holl. ii. 102, t. 250. H. revolutum. Col. in Tasmanian Journ. Nat. Sci. (1845) 26.
North and South Islands, Stewart Island, Auckland Islands: Abundant throughout. Sea-level to 3000 ft.
An abundant plant in most temperate and subtropical countries, and everywhere highly variable. Var. cupressiforme has much of the habit of the next species, but the valves of the indusium are spinulose-dentate.
18. H. unilaterale, Willd. Sp. Plant. v. 521.—Forming large patches on the ground among moss or on the roots of trees. Rhizome long, creeping, branched. Fronds 1–4 in. long, linear-oblong, dark-green, rigidly membranous, pinnate below, pinnatifid above. Stipes ½–1½ in. long, slender, wiry, naked; rhachis winged in the upper portion only. Pinnæ narrower and more rigid than in H. Tunbridgense, often pinnatifid on the upper side alone. Segments fewer and narrower, frequently decurved, usually involute, margins conspicuously spinulose-dentate. Sori terminal on short lateral segments near the base of the pinnæ on their upper margin, exactly as in H. Tunbridgense. Indusium obovate-oblong or broadly oblong, turgid, slightly immersed at the base, deeply 2-valved; valves smooth; margins quite entire.—Hook. f. Fl. Nov. Zel. h. 11; Fl. Tasm. ii. 134; Handb. N.Z. Fl. 353. H. Wilsoni, Hook. Brit. Fl. (edit. 1) 450; Sp. Fil. i. 95. H. Tunbridgense var. Wilsoni, Hook, and Bak. Syn. Fil. 67.
North and South Islands, Stewart Island: From Te Aroha Mountain southwards, not common, chiefly in mountain forests. Sea-level to 3500 ft.
Very closely allied to H. Tunbridgense, and sometimes hardly to be distinguished from it in the absence of fruit, but usually the frond is taller and narrower and more rigid, the pinnæ; are sparingly divided and decurved, the segments often unilateral, and the indusia narrower and more turgid, with the margins of the valves quite entire. Its geographical range is nearly the same as that of H. Tunbridgense, but it is a much less abundant plant.
19. H. multifidum, Swartz, Syn. Fil. 149, 378.—Forming matted patches upon the ground or on the trunks or branches of trees. Rhizome much branched, creeping, wiry. Fronds variable
