Nephrolepis cordifolia (L.) C. Presl - Fig, 1836

Hovenkamp PH & Miyamoto F, 2005, A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world, Blumea 50, pp. 279-322 : 294-296

5. Nephrolepis cordifolia (L.) C. Presl - Fig . 1j; Map 3; Plate 2d

Nephrolepis cordifolia (L.) C. Presl (1836) 79 ; Baker (1867) 300; Backer & Posth. (1939) 91; Copel. (1958) 186; Holttum (1968) 379; Tagawa & K. Iwats. (1985) 172; Proctor (1989) 262; Nauman (1992) 287; Verdc. (1996) 539; (2001) 7; Mickel & A.R. Sm. (2004) 405. - Polypodium cordifolium L. (1753) 1089 . - Aspidium cordifolium (L.) Sw. (1801) 32 ; (1806) 45. - Lectotype (Verdcourt, 1996): Ekman H11627 ( K), Hispaniola.

Polypodium auriculatum L. (1759) 1326 (nom. rej.). - Nephrolepis auriculata (L.) Trimen (1888) 152 ; Verdc. (1996) 540. - Lectotype (Verdcourt, 1996): Herb. Hermann s.n. ( BM), Ceylon.

Aspidium tuberosum Bory (1810) 234 . - Nephrodium tuberosum (Bory) Desv. (1827) 252 . - Nephrolepis tuberosa (Bory) C. Presl ( 1836) 79 . - Type: Anon. s.n. ( B-Willd., L, P), Réunion.

Nephrodium edule D. Don (1825) 5 . - Type: Hamilton s.n. (n.v.), India.

Aspidium imbricatum Spreng. (1827) 97 . - Nephrolepis imbricata (Spreng.) C. Presl (1836) 79. - Nephrodium imbricatum (Spreng.) Bojer (1837) 392 . - Type: Sieber 41 ( K), Mauritius.

Nephrolepis rhizodes Kunze (1848a) 236 . - Type: Zollinger 2526 ( L).

Nephrolepis intramarginalis Kunze (1850) 268 . - Type: Anon. s.n. cult. in hort. Lips. ( L), cultivated .

Nephrolepis flexuosa Colenso (1888) 231 . - Type: Colenso s.n. ( K).

Habit, rhizome morphology. Plants forming tufts of 3-7 fronds. Runners 0.5-1.5 mm thick, branching angle divaricate. Scales on runners very sparse to dense, spreading or squarrose (occasionally). Tubers present or absent. Fronds to 40-120 by 2-6 cm, stipe 4-15 cm long. Lamina base strongly reduced, tapering over 10-25 cm, basal pinnae 4-10 cm long, 0.7-1.7 cm distant, middle pinnae slightly to distinctly falcate. Sterile pinnae 1-3.3 by 3-9 mm, herbaceous, thick, base slightly to strongly unequal, basiscopic base rounded or cordate, acroscopic base cordate, distinctly to strongly auricled, margin in basal part dentate, towards apex deeply dentate, apex rounded or obtuse. Fertile pinnae 1.6-3.2 by 0.4-0.8 cm, otherwise similar to sterile ones. Indument. Basal scales pseudopeltate, spreading, 8 by 1 mm, central part light brown, dull, margin in basal part irregularly lacerate, not hyaline, towards apex denticulate, without marginal glands, apex narrow, not long uniseriate. Rachis scales sparse or dense, spreading, light brown, with lacerate base and a well-developed protracted entire acumen. Scales on lamina absent. Hairs on lamina absent or sometimes present, costa absent. Sori medial, 6-15 pairs on fully fertile pinnae, elongated, not impressed. Indusium lunulate or broad, attached at broad base.

Distribution - Africa: Madagascar, Mauritius, Seychelles, Sao Tomé, Cameroon; Asia: India, Sri Lanka, Burma?, China, Japan, Taiwan, Indochina: Tonkin; throughout Malesia; Pacifc: New Caledonia, New Hebrides; Australia: Queensland down to Northern end of NSW, Lord Howe Isl.; New Zealand (North Island, Norfolk, Kermadec); Pacifc Islands. Hawaii (cultivated?), Samoa. Often cultivated and possibly as garden escape in some localities.

Habitat & Ecology - In tropical regions mostly at middle elevations (800-2000 m), occasionally higher (collections from lower elevations are probably from cultivated plants), often in submontane or ridge forest, mostly terrestrial (often on rotting logs), rarely epiphytic; rarely in fully open situations. In subtropical areas often growing at lower elevation.

Notes - Runners in this species can be with or without scaly tubers, the presence of which (at least when judged from the presence in herbarium specimens) seems to be erratic, not correlated to other characters. They are produced mainly on underground runners - the aerial parts appear to form tubers more sporadically. In cultivation, the tubers can be observed to shrivel and disappear when plants are kept dry - in nature the presence may be similarly dependent on periods of moist conditions. For these reasons, it is impossible to use herbarium collections to assess the frequency with which tubers are formed.

In the Neotropics, N. cordifolia is at many sites apparently escaped from cultivation. It may be native perhaps only in the central portion of the range (Cuba to Venezuela).

KEY TO THE VARIETIES

1a. Rhizome short, fronds erect to arching, pinnae in a plane with the rachis..... 2 b. Rhizome elongate, forming a distinct erect trunk, fronds stiffly erect, pinnae perpendicular to rachis................................. c. var. pumicicola 2a. Pinnae with basiscopic base rounded to cordate, margins straight............................................................. a. var. cordifolia

b. Pinnae with basiscopic base narrowed, margins sinuose............................................................. b. var. pseudolauterbachii