Nephrolepis obliterata (R. Br.) J. Sm. - Fig

Hovenkamp PH & Miyamoto F, 2005, A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world, Blumea 50, pp. 279-322 : 306

14. Nephrolepis obliterata (R. Br.) J. Sm. - Fig . 1e; Map 4; Plate 2i

Nephrolepis obliterata (R. Br.) J. Sm. (1842a) 197 ; Fée (1852) 319. - Nephrodium obliteratum R. Br. (1810) 148 . - Aspidium obliteratum Spreng. (1827) 99 . - Arthropteris obliterata (R. Br.) J. Sm. (1866) 163 ; (1875) 225. - Type: Banks s.n. ( BM), Australia.

? Nephrolepis saligna Carruth. (1873) 361 . - Type: Seemann 743 ( BM), Fiji.

Habit, rhizome morphology. Plants forming tufts of 3 or 4 fronds. Runners 1-2 mm thick, branching angle divaricate. Scales on runners very sparse or sparse, appressed or spreading. Tubers absent. Fronds 100-170 cm long (or more), 12-33 cm wide, stipe 36-80 cm long. Lamina base truncate, tapering over 20-40 cm, reduced basal pinnae 4-8 cm distant, middle pinnae slightly to distinctly falcate. Sterile pinnae 6-15 by 1.3-2.4 cm, herbaceous, thick, base strongly unequal, basiscopic base rounded, acroscopic base cuneate or truncate, not auricled, margin in basal part crenate, apex acuminate or caudate, cauda to 3 cm long. Fertile pinnae 7-17 by 0.9-2.1 cm, more strongly dentate between the sori and more gradually narrowed than the sterile pinnae to an acute apex without a distinct cauda. Indument. Basal scales peltate, appressed (rather sparse), 2.5 by 1 mm, central part dark brown, dull, hyaline margin wide, distinct, fmbriate in basal part, marginal glands absent. Transition to rachis scales abrupt. Rachis scales very sparse, without a distinctly protracted acumen, appressed and often very inconspicuous, hyaline. Scales on lamina absent. Hairs on lamina absent, costa absent. Sori marginal (often on teeth), 30-45 pairs on fully fertile pinnae, round. Indusium reniform, with narrow sinus or reniform, with open sinus, attached at sinus.

Distribution - Moluccas, New Guinea, New Britain, Solomon Islands, Vanuatu, New Caledonia, Pacifc Islands: Carolines. Australia: Queensland. Any reports from Fiji and Samoa are doubtful: None of the specimens seen could be unambiguously identified as this species.

Habitat & Ecology - Usually at low elevations, from sea level to 300 m, occasionally to 1000 m. In various types of forests or plantations, in mangroves and swamp forest; often abundant in undergrowth, in clearings or on riverbanks and forest margins, also as low epiphyte on tree trunks or on fallen trees.

Notes - The name N. saligna has been frequently applied to specimens of this species, but its application is not certain. Of the available type material, one specimen (Seemann 7530, marked as type of N. saligna in K) is N. brownii , two others (Banks & Solander s.n., s.d.; Home s.n., 1853, Fiji, both BM) are N. biserrata , a fourth specimen (Seemann 743, BM) is sterile and lacks the basal scales necessary for a reliable identifcation.

The name Nephrodium obliteratum R. Br. has often been taken be a synonym of Arthropteris palisotii (Desv.) Alston , however, the type (Banks s.n., BM) clearly is a Nephrolepis species.

Nephrolepis obliterata is not easy to characterize. It usually has quite large pinnae, with nearly marginal sori. Characteristically, they are gradually narrowed from close to the base upwards, and gradually falcate from ± 1/2, sometimes all the way from the base. The best distinguishing characters are in the indument. The indument of N. obliterata differs from that of N. biserrata , with which it has often been confused, in the scales at the base of stipe being closely appressed, with a rather sharp transition to sparse, appressed, very translucent and inconspicuous peltate scales upwards on the stipe and on the rachis. The very sparse, inconspicuous rachis scales and the absence of hairs on the costae also distinguish it from N. davallioides , N. brownii or N. falcata . In addition, N. brownii has usually less distinctly falcate pinnae, and those of N. falcata are usually smaller.