Amauropelta glabrescens 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 : 11-12

Amauropelta glabrescens A.R.Sm. , sp. nov. ( Fig. 2 )

Differing from Amauropelta pachyrhachis (Kunze ex Mett.) Salino & T.E.Almeida , and from most other members of sect. Pachyrhachis (see Smith 1974) in having laminae that lack sessile, orangish, resinous glands abaxially.All species in sect. Pachyrhachis have erect or suberect rhizomes. From A. metteniana (Ching) Salino & T.E.Almeida it further differs in having glabrous indusia.

Type:— BOLIVIA. La Paz: Prov. Nor Yungas, Cantón Pacollo, Cerro Hornuni, Quebrada en el Cerro Hornuni, 16º11’S, 67º52’W, 1850 m, A. Portugal 542, with J. Gonzales, A. Romero (holotype UC!; isotype LPB) .

Plants terrestrial; stems suberect to erect; petioles stramineous, darkened at only at the very base, to ca. 20 cm × 2–3 mm, proximally with numerous scattered scales, proximally with only a few scales, these dull brown, ovate-lanceolate, glabrous or nearly so, scales lacking distally; leaves to ca. 90 cm long; blades chartaceous, pinnate-pinnatifid, proximal ca. 9 pinna pairs gradually reduced, the shortest ca. 1 cm long, blade apex confluent, pinnatifid, gradually tapering; rachises stramineous, glabrous or glabrescent abaxially; pinnae sessile or nearly so, opposite proximally, becoming alternate distally, widest at the base, to 10 × 1.8 cm, deeply pinnatifid or nearly pinnatisect to within 1 mm of costae, segments 3–4 mm wide; aerophores lacking at pinna bases; laminar buds lacking; veins 5–8 pairs per segment, lowermost pair from adjacent segments meeting margins well above sinuses; costal scales lacking; costae, veins, and margins glabrous abaxially, or nearly so, laminar surfaces between veins glabrous, glands apparently lacking, indument adaxially principally only along costae, costules, veins, and laminar tissue between veins lacking hairs; sori medial, round, discrete; indusia present, persistent, glabrous, round-reniform, to ca. 0.8 mm diam.

Range:— Known with certainty only from Bolivia ( LP).

Ecology:— Rare; terrestrial on wet slopes; 1850 m.

Notes:— This species appears to be allied to A. pachyrhachis (Kunze ex Mett.) Salino & T.E.Almeida , widespread in the neotropics, and also to several Brazilian species: A. tenerrima (Fée) Salino & T.E.Almeida and A. metteniana , both from southern Brazil. An unidentified remarkably similar specimen from Est. São Paulo, Salino 1675 (UC), may be this species.

Figures

FIGURE 2. Amauropelta glabrescens. A. Habit. B. Medial pinna. C. Pinna segments, abaxial surface detail. D. Pinna segments, adaxial surface detail. E. Sorus. (All from the holotype: A. Portugal 542)