Flora of New Zealand Series

A. affine auct. non  Willd. Sp. Pl. 5, 1810, 448.

A. formosum A. Rich. Essai Fl. N.Z.1832, 88.

A. pullum Col. in T.N.Z.I. 25, 1873, 319.

Rhizome stout, far-creeping, clad in stiff linear-attenuate dark brown paleae, up to 8 mm. long; stipites distributed along rhizome. Stipes wiry, shining, dark purple to almost black, scabrid towards paleate base; 8-25-(40)cm. long. Rhachis wiry, blackish purple, flexuose, glab.; secondary rhachides sts ± pubescent. Lamina 15-30-(40) × 7-20- (25) cm., ovate to narrow deltoid, bi- to tri-pinnate below, pinnate above, firm, pale to rather dark green above, ± glaucous below, glab. Primary pinnae up to 12 × 5 cm., ovate to oblong; secondary up to 4 × 2 cm.; terminal pinna up to 20 cm. or more long. Pinnules dimidiate-oblong to dimidiate-rhomboid or rhomboid; fertile 10-25 × 5-12 mm.; sterile up to 30 × 15 mm., with often acute lobes; lower margin entire, straight to concave-convex; upper margin with alternately shallow and rather deep crenate lobes. Sporangia in sinuses of shallower lobes, up to 14 groups per pinnule, protected by orbicular- reniform to lunulate, ± crenulate to toothed reflexed margins 1·5-2 mm. diam.

DIST.: K., N., S., St., Ch. Lowland forest throughout. Endemic.

Whether the N.Z. rather polymorphic forms should be merged into A. affine, as has been customary, is a moot point requiring further comparative study. Hooker (Fl. N.Z. 2, 1855, 20, 21) records both A. affine and A. cunninghamii for N.Z. His chief points of differentiation are: A. affine --stipes and rhachis slender, smooth; frond flaccid, membr., upper surface with a few scattered black hairs; involucres remote, pale. A. cunninghamii --stipes stouter, sts scaberulous at base; fronds less membr., without hairs; sinus of involucres always very narrow and deep. He retains both spp. in his later treatment (Handbk N.Z. Fl. 1864, 359, 360).

Colenso (T.N.Z.I. 20, 1888, 218) describes a crested form collected "on limestone crags at Moteo, Puketapu District, near Napier; 1885: Mr. A. Hamilton " as var. heterophyllum of A. affine Willd. " Plant pale green, suberect, 10-14 inches high, forming large tufts . . . stipes . . . with a few short hairs at the base. Fronds bipinnate . . . branches simply pinnate, their tips crested . . . pinnae very irregular, large and small mixed, of various sizes and shapes . . . ""A. pullum Col. in T.N.Z.I. 25, 1893, 319, from " open land, damp shaded spots rocky places, between Dannevirke and the East Coast, County of Waipawa, 1892, Mr. H. Hill," deserves further study. The points emphasized by Colenso are: "scales black, large, acuminate, glossy . . . fronds always more or less dark-coloured on both surfaces, some pinnae are nearly black . . . pinnules of various shapes and sizes on the same plant . . . the upper margins cartilaginous laciniate and serrate, teeth large, white hard and sharp . . ." Specimens in W (" Dannevirke, Hawkes Bay, H. Hill ") agree fairly well with the description; the paleae are dark, subulate- attenuate, c. 3 mm. long.

Field (Ferns of N.Z. 1890, 81) remarks under A. affine " It also occurs at the Chatham Islands, the variety " Chathamicum " found there being very coarse. " Cheeseman (Man. N.Z. Fl. 1925, 73) remarks " Most of the Chatham Islands specimens. that I have seen are less compound, with larger and coarser narrower pinnules "; the pinnules may be as much as 3 × 1·5 cm., dimidiate-rhomboid to subrhomboid; upper margin rather deeply lobed, lobes rather coarsely and sharply toothed.