Amauropelta boliviana A.R.Sm., 2017

Smith, Alan R. & Kessler, Michael, 2017, Prodromus of a fern flora for Bolivia. XXX. Thelypteridaceae, Phytotaxa 331 (1), pp. 1-34 : 7

Amauropelta boliviana A.R.Sm. , sp. nov. ( Fig. 1 )

Distinguished from related species by the tall, narrow, erect caudices only 1 cm wide; abruptly reduced proximal pinnae, the lowest ca. 1 mm long; small, barely visible indusia; nearly glabrous costae and lamina abaxially (hairs, if present, confined to the proximal regions of the costae); and numerous adpressed hairs on the laminar tissue between veins adaxially.

Type:— BOLIVIA. Cochabamba: Prov. Carrasco, campamento Sehuencas, segundo sitio de “camping”, pasando el puente del Río Fuerte , 17º29’81”S, 65º16’38”W, 2250 m, I. Jimenez 213 (holotype UC!; isotype LPB) .

Plants terrestrial; stems erect, caudices very narrow, to 10 × 1 cm; petioles stramineous, darkened at only at the very base, to ca. 20 cm × 2 mm, proximally with a few scales, these brown, ovate-lanceolate, to ca. 4 × 1.5 mm, glabrous, glabrescent, or sparsely hairy, scales lacking distally on stipes; leaves to ca. 85 cm long; blades chartaceous, pinnate-pinnatifid, proximal ca. 5 pinna pairs abruptly reduced, the shortest ca. 1 mm long, blade apex confluent, pinnatifid, gradually tapering; rachises stramineous to tan, glabrous or glabrescent abaxially; pinnae sessile or petiolulate <1 mm, opposite or subopposite proximally, becoming alternate distally, widest just beyond the base, to 9 × 2 cm, deeply pinnatifid or nearly pinnatisect to within 1 mm of costae, segments 3–4 mm wide; aerophores lacking at pinna bases; lamina buds lacking; veins 8–10 pairs per segment, lowermost pair from adjacent segments meeting margins well above sinuses; costal scales lacking; costae, veins, and margins glabrous abaxially, or with sparse, straight hairs, also with tiny stipitate glands 0.05 mm long on costae and laminar surfaces between veins, sessile resinous glands lacking; indument adaxially along, costae, costules, veins, and laminar tissue between veins, costal hairs on ridges, 0.2–0.4 mm long, ascending, hairs on laminar tissue ca. 0.2 mm long, adpressed; sori medial, round, discrete; indusia present, small and difficult to see in mature fronds, glabrous or slightly ciliate and stipitate-glandular on margins, round-reniform, to ca. 0.5 mm diam. and seemingly fragmentary at times.

Range:— Bolivia ( CO).

Ecology:— Rare, known only from the type; terrestrial in montane, evergreen cloud forests; 2250 m.

Notes: —Nearest affinities are uncertain, but possibly with A. ptarmiciformis . That species has much more numerous, longer, stouter hairs on the costae abaxially and smaller, more delicate fronds.

Figures

FIGURE 1. Amauropelta boliviana. A. Habit. B. Medial pinna. C. Pinna segments, adaxial surface detail. D. Pinna segments, abaxial surface detail. E. Sorus. (All from the holotype: I. Jimenez 213)