Nephrolepis undulata (Afzel.) J. Sm. - Map

Hovenkamp PH & Miyamoto F, 2005, A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world, Blumea 50, pp. 279-322 : 310-312

19. Nephrolepis undulata (Afzel.) J. Sm. - Map 3

Nephrolepis undulata (Afzel.) J. Sm. (1845) 35 ; Pic. Serm. (1969) 273; Proctor (1989) 261; Nauman (1992) 288; Verdc. (2001) 5; Mickel & A.R. Sm. (2004) 409. - Aspidium undulatum Afzel. in Sw. (1801) 32; Sw. (1806) 45. - Nephrolepis tuberosa (Bory) C. Presl var. undulata (Afzel.) Kuhn (1868) 156 . - Nephrolepis cordifolia (L.) C. Presl var. undulata (Afzel.) C. Chr. (1906) 453, 455 . - Nephrolepis undulata var. undulata (Afzel.) Verdc. (2001) 5 . - Type: Anon. s.n. ( BM).

Nephrolepis occidentalis Kunze (1844) 243 [= 343] . - Nephrolepis cordifolia (L.) C. Presl var. occidentalis (Kunze) Krug (1897) 121 . - Nephrolepis pectinata (Willd.) Schott var. occidentalis (Kunze) Urb. (1925) 316 . - Type: Roemer 27 ( BM? n.v.), Mexico.

Nephrolepis delicatula M.J. Decne. (1844) 178, t. 179 ; Pic. Serm. (1969) 275; Tagawa & K. Iwats. (1985) 174. - Nephrolepis tuberosa (Bory) C. Presl var. delicatula Hook. (1846) 151 . - Nephrolepis undulata (Afzel.) J. Sm. var. delicatula (M.J. Decne.) Verdc. (2001) 7 . - Type: Jacquemont 598 ( K, P), India.

Nephrolepis intermedia Fee (1857) 32 (non Sodiro 1893). - Type: Schaffner 447 ( K), Mexico.

Nephrolepis pluma T. Moore (1878a) 588, f. 108. - Type: Anon. s.n. ( K).

Nephrolepis glabra Copel. (1906) 146 ; (1958) 186. - Type: Copeland 1819 ( KYO, MICH, P, SING), Philippines.

Nephrolepis flipes H. Christ (1909b) 213 . - Type: Gillet 3126 ( P), Congo. Nephrolepis cordifolia (L.) C. Presl var. compacta Bonap. (1923) 265 ; Pic. Serm. (1969) 273. - Type: Bequaert 3018 ( BR, teste Pichi Sermolli).

Nephrolepis paucifrondosa J.F.R. Almeida (1926) 51 . - Type: J.H. Lace 4940 ( K).

Habit, rhizome morphology. Plants forming tufts of 2 or 3 fronds. Runners 0.5- 1 mm thick (or thinner), branching angle divaricate. Scales on runners very sparse or sparse, spreading. Tubers present. Fronds 50-90 cm long (or longer), 5-7 cm wide, stipe 6.5- 15 cm long. Lamina base strongly reduced, tapering over 8-15 cm, basal pinnae 0.6 cm long, 2-4 cm distant, middle pinnae straight to distinctly falcate. Sterile pinnae 2.9-3.2 by 0.6-0.8 cm, herbaceous, thin, base slightly unequal, strongly unequal or fully one-sided, basiscopic base cuneate or cordate, acroscopic base cordate, auricled (often dilated and crossing the rachis), margin in basal part crenate or dentate, towards apex dentate or deeply dentate, apex acute. Fertile pinnae 2.1-3.5 by 0.5-0.7 cm, the base often more distinctly one-sided and the margin more deeply dentate than the sterile pinnae. Indument. Basal scales peltate, spreading, 3.5 by 0.5 mm, straw-coloured or hyaline, dull, margin in basal part irregularly lacerate with a few protrusions, in acumen entire, marginal glands absent. Rachis scales very sparse (persistent only around the pinna-bases), with a well-developed spreading, ciliate acumen, or completely dissected into narrow filaments, with hyaline or dark glandular apical cells. Scales on lamina absent. Hairs on lamina frequently present (very inconspicuous), on costa absent. Sori submarginal or medial, 6-10 pairs on fully fertile pinnae, elongated, slightly impressed. Indusium lunulate or broad, attached at broad base.

Distribution - Worldwide. Widespread in Africa and Tropical Central and South America. In Asia there is a distinct distributional centre from Indochina to Northern

India, but N. undulata occurs scattered elsewhere: Malabar, Kerala, Madras, Philippines.

Habitat & Ecology - Usually terrestrial, in grassland, brushwood or forest, or epilithic, on cliffs, lava flows or rocky outcrops, rarely indicated as epiphytic, altitude 300-2450 m.

Notes - The name N. undulata has been applied traditionally to the form occurring in Africa, which is relatively robust. The smaller forms from Asia have been named N. delicatula , or N. paucifrondosa , while the forms from the Americas were distinguished as N. occidentalis by Nauman (1985, 1992).

Nephrolepis undulata is here distinguished from N. cordifolia by the seasonal mode of growth, with new fronds sprouting each season from underground tubers. In most cases, no more than two well-developed fronds develop in a single season, and in many cases collections contain only plants with a single frond. The frst sprouting frond in N. undulata is usually the largest one and remains connected to the tuber by a subterraneous, somewhat sinuous, glabrous stem. If other fronds develop, they do so from a bud that appears to be in a lateral position on the base of the stipe of the frst frond, not from a distinct rhizome. Despite the usually slender stature of the tufts, individual fronds, especially the frst one, can be quite large. Apart from this characteristic growth form, this species can usually also be distinguished from N. cordifolia by the more glabrous stipe and rachis, the basal part of which is often conspicuously thicker than in N. cordifolia , and the, especially in comparison to the stipe, thin runners originating from the rhizome bud. According to Fraser-Jenkins (pers. comm.) the tubers of specimens in Nepal are more elongated than those of N. cordifolia . In African material, a large number of mature tubers seen are also elongated, but this is not always the case. Despite these differences, the possibility cannot be completely excluded that this description is based on an ecologically correlated set of characters that have developed independently in separate populations of N. cordifolia , in response to the requirements imposed by a strongly seasonal climate.

HYBRIDS AND SUSPECTED HYBRIDS