Flora of New Zealand Series

Pteris falcata R. Br. Prodr. 1810, 154.

P. seticaulis Hook. Ic. Pl. 1840, t. 207.

Platyloma falcata J. Smith in J. Bot. 4,1841,160.

Rhizome stout, creeping, clad when young in pale to dark brown subulate-attenuate paleae, c. 3 mm. long; stipites clustered along rhizome. Stipes rather stout, erect to spreading, wiry, very dark brown, 5-15- (25)cm. long, clad in dark brown squarrose, stiff, linear-attenuate paleae c. 5 mm. long, mingled with hairs, becoming glab. (rarely glabrate also when young). Rhachis similar to stipes, bearing numerous, (up to c. 40 or more pairs) subopp. to alt. pinnae. Lamina coriac., dark dull green above, paler below, ± paleate below, veins hidden; (20)-30- 40-(50) × 3·5-7·5 cm. Lower pinnae shortly stalked, subpandurate, obtuse, widened at cordate-truncate base, with small tooth near base of upper margin. Mid pinnae 2-5 cm. × 5-10 mm., shortly stalked, shading into uppermost sessile smaller pinnae; about lanceolate-oblong, subpandurate, subfalcate, caudate-truncate at base, us. apiculate at acute to subacute apex; auricle varying from a triangular tooth to 1cm. × 5 mm., obtuse to subacute. Sori in broad band near margin, reaching nearly to apex and to base on lower side, up to 4·5 cm. × 3 mm., at first protected by reflexed margin.

DIST.: K., N., S. Lowland to montane forest and rocky places to lat. 46° 30', local. Also Tasmania, Australia, Malaya and India.

Very distinct in their extreme forms, the two spp. are linked by a series of intermediate forms of quite uncertain status. Forms with variously lobed pinnae are met with. Cheeseman (Man. N.Z. Fl. 1925, 66) remarks of P. falcata, " All the New Zealand specimens that I have seen have shorter and broader pinnae than the typical state, and approach P. rotundifolia so closely as to make it probable that the two species are forms of one plant. " Cockayne and Allan (Ann Bot., Lond. 48, 1934, 8) suggested that the two spp. possibly hybridize. Crookes (Dobbie N.Z. Ferns 1951, 204) records studies by the late Miss E.F. Kibblewhite, who " transplanted an (apparently) perfectly normal form of P. falcata to her fernery. The rhizome grew out, creeping on to a somewhat exposed position where there was little soil. It put forth fronds in which the pinnae had entirely lost the characteristic 'sickle shape' form. They were absolutely flat, distinctly rounded, and stood out exactly at right-angles to the rachis. Indeed they differed only from the normal P. rotundifolia in being longer. "