Phlegmariurus curvifolius B. Ollgaard 2012

. Phlegmariurus curvifolius (Kunze) B. Øllgaard (2012b: 14). Fig. 10C

Lycopodium curvifolium Kunze (1835: 5).— Lycopodium tenue Willdenow var. tenuissimum Spring (1849: 21).— Urostachys curvifolius (Kunze) Nessel (1939: 129).— Huperzia curvifolia (Kunze) Holub (1985: 72). Type:— PERU. Huaìnuco: “sylvar. densarum arboribus prope Pampayaco”, 1829, Poeppig s.n. (AWH, B, BR, E, G, K, M, NY, W).

Lycopodium cernuum Linnaeus (1753: 1103) var. tenerrimum Nessel (1940 a: 173). Type:— ECUADOR: Without locality, Sodiro n. 3101” (BONN-Nessel 535).

Delicate to extremely delicate plants, flaccidly pendulous, to 60 cm long. Shoots gradually heterophyllous, 2.5–6 mm in diameter including the leaves in basal divisions, tapering to 0.3–1.5 (–2) mm in diameter including leaves in terminal divisions. Stems excluding leaves 0.4–0.7 mm thick at the base, tapering to 0.2–0.4 mm upward, greenish to stramineous, usually not concealed by leaves, to more than 10 times dichotomous, usually sparsely sporangiate from 10–20 cm above the base and upward. Leaves of basal divisions borne in alternating whorls of 4–5, these 1–2 mm apart, forming 8–10 indistinct longitudinal ranks, patently sigmoid to strongly falcately upward curved, acicularfiliform, long and widely decurrent, 2–4 (–6) x 0.2–0.5 mm, extremely delicate, abaxially convex, flat or canaliculate above. Vegetative leaves of terminal constricted divisions alternate, or borne in alternating irregular whorls of 3, usually closely appressed, lanceolate to linear-lanceolate, somewhat clasping with the base, 1.2–3.5 × 0.2–0.6 mm, usually strongly involute, often sharply carinate at the base, short to long decurrent. Sporangia usually few, borne, often unilaterally, in the axils of every third to fifteenth (or more) leaf along the terminal shoots. Sporophylls conform, or shorter and wider, lanceolate to widely ovate, or subcordate and short to long acuminate, usually widely spreading, 1–3 × 0.3–0.8 mm, in ultimate divisions sometimes scarcely exceeding the sporangia, abaxially with a prominent vein, or carinate. Sporangia 0.6–0.8 mm wide.

­­­ Distribution:— Costa Rica to Peru.

­­­ Habitats:— Epiphytic in middle elevation montane forest, elev. 1000–2300 m elev.

­­­ Notes:— Phlegmariurus curvifolius is variable in size and compactness. This variation may probably not be explained by environmental factors alone. The species is most easily recognized by the strongly upward curved (falcate) leaves of basal divisions, and the appressed non-sporangiate leaves of the narrow, terminal divisions. The smallest forms with hair-like terminal shoots (Andes) represent the most fragile and slender extreme known in the family. They correspond to the type collection.

Part of the material referred to this species was earlier referred to Lycopodium verticillatum L. f. var. parvifolium (Nessel) Lellinger, 1989: 41–43.— Urostachys verticillatus (L. f.) Herter var. parvifolius Nessel, Revista Sudamer. Bot. 6: 163, f. 43 (1940).— Huperzia curvifolia (Kunze) Holub var. parvifolia (Nessel) B. Øllgaard, Novon 3: 71 (1993).— Type: Costa Rica, Volcan Barba, Brade & Brade 283 (HB, BONN-Nessel no. 247)

The material here treated as P. curvifolius is highly variable and referred here tentatively. Most specimens are somewhat intermediate between Phlegmariurus acerosus and P. curvifolius var. curvifolius (Andes). Some specimens approach slender forms of P. filiformis. In general, the distinction of species in this group is problematic. The material earlier referred to var. parvifolius has slightly thicker stems, and is larger, with slightly less closely appressed nonsporangiate leaves in terminal divisions but shares the upward curved leaves in proximal divisions with the type variety.

­­­ Specimens­­­studied:­­­ Chiriquí: Fortuna Dam (Hornito), Correa et al. 2505 (MO, NY, QCA). S.O. del campamento de Fortuna (Hornito) sitio de presa subiendo hasta la finca de Pittí, 1000–1200 m Correa et al. 2385, 2597, 2678 (PMA); ibid., Correa et al. (PMA). East of the Fortuna Dam site, Mendoza et al. 186 (PMA). Valley of Río Piarnasta, above El Boquete, 1525–1550 m, Killip 5149 (US). 0.8 km up the main road from the center of the town Cerro Punta, then 1.2 km SW along side road on ridge beyond end of the road, primary forest, 2100–2300 m, Lellinger et al. 1945 (US). Panamá: Croat 15850 (MO). Coclé: Parque Nacional General de Div. Omar Torrijos Herrera, Araúz & Flores 783A (PMA).