Campyloneurum amphostenon (Kunze ex Klotzsch) Fée

Authority

Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

Family

Polypodiaceae

Scientific Name

Campyloneurum amphostenon (Kunze ex Klotzsch) Fée

Description

Species Description - Rhizomes moderately long-creeping (>5 mm between stipe bases), pruinose, (2–)3–5 mm diam.; rhizome scales dense, tan to brownish, ovate-lanceolate, 3–6 x (1–)1.5–2.5 mm, clathrate, the cells elongate, at least twice as long as wide; fronds 30–70(–100) cm long, usually somewhat distant (often 5–10 mm apart); stipes mostly 3–10 cm long; 1/10–1/5 the length of the blades; blades subcoriaceous, narrowly elliptic, (1–)1.7–3.5 cm wide, bases subabruptly tapering, apices acuminate; lime dots absent adaxially; areoles 2–4(–5) rows between midribs and margins, excurrent veinlets 1 or 2 per primary areole; main lateral veins immersed, faintly if at all discernible, secondary veins irregularly anastomosing; sori 2–4-seriate, in ± irregular rows between midribs and blade margins, one or two sori per primary areole.

Discussion

Polypodium amphostenon Kunze ex Klotzsch, Linnaea 20: 399. 1847. Polypodium angustifolium Sw. var. amphostenon (Kunze ex Klotzsch) Baker in Martius, Fl. Bras. 1(2): 530. 1870. Campyloneurum angustifolium (Sw.) Fe´e var. amphostenon (Kunze ex Klotzsch) Farw., Amer. Midl. Naturalist 12: 296. 1931. Type. Venezuela. Me´rida, Moritz 120b (holotype B; isotypes BM, K!, frag. NY!).

This species is closely related to C. angustifolium, with which it has often been combined. Campyloneurum amphostenon differs from that in having broader blades (and hence more rows of sori between the midribs and blade margins), longer stipes, and longer and wider, lighter colored rhizome scales. We have seen one mixed collection of the two species, Dorantes et al. 5120 (NY), from Edo. Veracruz, Las Vigas, 2200 m, and on this gathering, the differences in rhizome scales and soriation can readily be seen. Schaffner 76 (NY) is represented by two sheets, one labeled “Valle de Me´xico” collected in 1875, the other labeled “San Lui´s Potosi´” with no collection date. Leo´n (1992) recognized C. amphostenon var. irregulare (Lellinger) B. Leo´n as also occurring in Mexico, and cited a single collection, from Veracruz: Nee & Hansen 18701 (F).We have not seen this specimen, but doubt its distinctness from var. amphostenon. Var. irregulare (type from Ecuador) was said (by Leo´n) to be distinguished by the irregular arrangement of the cells in most of the stem scales; it was ascribed a range of s. Mexico (Ver), Guatemala, Costa Rica, Panama, Ecuador, Peru, and Bolivia by Leo´n. Leo´n (1992; in Davidse et al., 1995) cited Mexico in the range of C. densifolium (Hieron.) Lellinger, a species said to occur from Mexico to Bolivia and the Greater Antilles. Campyloneurum densifolium was distinguished by Leo´n by light brown, ovatelanceolate (vs. dark brown and lanceolate) subappressed (vs. spreading) rhizome scales generally two times longer than wide (vs. three or more times longer than wide in C. amphostenon); in addition, the cells of the scales were said to be almost isodiametric in C. densifolium (vs. longer than wide in C. amphostenon). The distribution of C. densifolium in Mexico was given by Leo´n as Durango (Ownbey & Ownbey 1935, GH, NY, US) and San Lui´s Potosi´ (Pringle 3821, BM, F, GH, MO, NY); we have seen both of these gatherings in various herbaria and regard the former as C. ensifolium and the latter as C. angustifolium. There are specimens from southern Mexico, especially Chiapas, that possess some of the characteristics of C. densifolium, but we are not convinced that the species can be distinguished insofar as Mexican specimens are concerned.