Cyathea margarita Lehnert, 2016

Lehnert, Marcus, 2016, A synopsis of the exindusiate species of Cyathea (Cyatheaceae-Polypodiopsida) with bipinnate-pinnatifid or more complex fronds, with a revision of the C. lasiosora complex, Phytotaxa 243 (1), pp. 1-53 : 38-40

48. Cyathea margarita Lehnert , sp. nov. ( Fig. 9 )

A new exindusiate species of Cyathea with submarginal to marginal soral position that differs from similar species in the dense, even pubescence of short, straight hairs on the laminae abaxially: Cyathea praecincta with marginal sori and C. brunnescens with supramedial to submarginal sori lack these hairs, and C. tortuosa has only few, mostly tortuous hairs abaxially.

Type: — ECUADOR. Pichincha: Saguangal, Hacienda La Conquista, 00º14’N, 78º47’W, 800 m, 3 November 1995, B. Øllgaard, H. Navarrete, C. Kragelund & H. Ankersen 1133 (holotype QCA!, isotype AAU!).

Trunks to 5 m tall, ca. 4 cm diameter, presumably shedding old petioles, adventitious buds not reported. Fronds to ca. 200(–350?) cm long. Petioles to 62(–200?) cm long, inermous to weakly aculeate, yellowish to sramineous in dried material, no scurf, no hairs. Petiole scales to 19 x 3.0– 3.5 mm, ovate lanceolate with attenuate, straight to falcate tips, dark castaneous, almost black, with thin, whitish to yellowish margins, hardly notable. Laminae to ca. 150 x 100 cm, bipinnate-pinnatifid, apices gradually reduced. Rhachises inermous. Axes (rhachises, costae, and costules) densely hairy, adaxially to 1 mm long, artorsely curved to appessed, abaxially hairs shorter (0.5 mm) but more numerous and spreading, also with few, thin whitish to tan, partially hyaline scales, both strap like (to 6.0 x 0.2–0.5 mm) or ovate (to 3 x 2 mm). Pinnae to 52 cm long, sessile or stalked to 1.8 cm, patent to weakly ascending, basal pair ca. ½ the length of longest pinnae, with pinnules shorter and blunter. Pinnules to 70 x 20 mm, sessile to subsessile, linear-lanceolate with obtuse to long-acute tips, segments to 11 x 6 mm, oblong-deltate, obtuse, weakly falcate, margins entire to weakly crenulated at segment apices; veins yellow, prominulent, simple, with abundant multicellular white hairs ca. 0.5 mm long on and between them abaxially, the same hairs sparsely on veins adaxially, white bullate squamules to 2 mm long with subulate tips, sparse abaxially. Sori marginal to submarginal, to 1 mm diameter, 10–20 sporangia per sorus, receptacles globose, 0.2–0.3 mm diameter, paraphyses abundant, thin hyaline, straight, longer than the sporangia (0.4–0.6 mm). Spores not examined.

Distribution and habitat: —Pacific slopes of the Andes in Colombia and Ecuador, also expected in Panamá in the Serranía de Darien, in perhumid montane and lowland forests at 20–1540 m.

Etymology: —The epithet refers to the locality of the Ecuadorean paratype, “La Perla” (Latin, margarita = pearl; noun in apposition). It is also intended as a mnemonic trick for the position of the sori, by sounding similar to marginal (the epithet “ marginalis” is not available anymore).

Additional specimens examined (paratypes): — COLOMBIA. Chocó: Trail above water supply impoundment W of Puerto Mutis ( Bahía Solano ), [ca. 6.22499, -77.408087,] 20–100 m, 25 January 1971, D. B. Lellinger & E. R. de la Sota ( COL) ; along the Río Monomacho (tributary of the Río Guale) in the foothills of the Serranía de Darien ca. 8–10 km W of Acandí , [ca. 8.526658, -77.374484,] 100–150 m, 18 March 1971, D. B. Lellinger & E. R. de la Sota 698 ( COL). Risaralda: Road from Uribe towards Mistrato, 05°24.074’N, 75°54.778’W, 1540 m, 19 February 2015, M. Lehnert 3159 ( BONN, MDE, Z) .

ECUADOR. Santo Domingo de los Tsáchilas [as Pichincha]: Bosque Protector “La Perla”, Km 41 de la carretera Santo Domingo-Quinindé, 00º00’49”–02’08”S, 79º22’21–32”W, 220 m, 11 August 1990, V. Zak, E. Guerrón & E. Terneus 5623 (QCA).

Remarks: — Cyathea margarita stands out among Ecuadorian Cyathea in having marginal to submarginal sori. It is superficially similar to C. brunnescens and C. tortuosa Moran (1991: 99) , whose sori are also closer to the margins than the midveins (supramedial to submarginal) but not as pronounced so as in C. margarita . Cyathea margarita differs chiefly in the strong pubescence of straight whitish hairs on and between the veins abaxially (vs. glabrous in C. brunnescens and hairs sparse on veins in C. tortuosa ). It also has straight paraphyses that are longer than the sporangia (vs. just of the same length as the sporangia in C. brunnescens and C. tortuosa ). The laminar squamules are mostly flat to weakly bullate and range from almost colorless to tan with white tips (vs. squamules concolorous brown, often strongly bullate). The only other sympatric species with clearly marginal sori is Cyathea bipinnata ( Tryon 1986: 33) Moran (1995: 53) , which has hemiteliod indusia and more or less entire pinnules (vs. indusia absent and pinnules pinatifid in C. margarita ). Both species are restricted to the Chocó biogeographic region in western Colombia and northwestern Ecuador.

Cyathea praecincta ( Kunze 1839: 53) Domin (1929a: 263) from eastern Brazil also has marginal sori but is abaxially glabrous and usually has larger segments than C. margarita .

Figures

FIGURE 9. Cyathea margarita, sp. nov. A. Petiole scales. B. Central pinna, adaxially. C. Fertile pinnule, abaxially. D. Fertile segment, abaxially. (All from the holotype)