Nasa sanchezii T.Henning & M.Weigend, 2011

Henning, T. & Weigend, M., 2011, Two new species of Nasa (Loasaceae) from Andean South America, Phytotaxa 26, pp. 1-8 : 3-4

Nasa sanchezii T.Henning & M.Weigend , spec. nov. ( Figs. 1–3 )

Plantae erectae, ramosae, usque ad 60 cm altae. Caulis basi ad 2–6 mm diametro, setis flavescentis et pilis scabridis brevissimis obtectus. Folia alterna,, lamina ovata, basi cuneata, apice acuminata, margine lobata, lobis 2–(3–7) in uno latere, triangulari-ovatis margine serratis. Calyx tubo turbinato, lobis ovati-acuminatis, 4 mm longis et 1,5– 2 mm latis; corolla expansa; petala alba, basin versus flava, oblonga, cymbiformia, 8–11 mm longa, 3–4 mm lata, dente triangulari in utrisque lateribus 2–3 mm a basi remoto provisa, dorso esetosa et dense pilis scabridis instructa.

TYPE:— PERU. Dept. Amazonas: Prov. Bongará. Río Utcubamba , 12 km below Caclic, 1420 m, 21 March 1964, P.C. Hutchison & J.K. Wright 4473 (holotype USM, isotypes F, MO, NY, UC, US) .

Annual herb 20–60 cm tall, densely branched from base, branches basally decumbent, 2–6 mm thick near base, sparsely covered with yellowish-brown setae 1.5–2.0 mm long and densely covered with glochidiate trichomes, decorated with dark green stripes. Leaves petiolate, lower petioles 35–55 mm long, sparsely setose, upper leaves subsessile; lamina rhomboidal to widely ovate, 40–110 mm long, 35–60 mm wide, base cuneate, truncate to rounded, margin lobed with 2–(3–7) triangular lobes on each side, lobes ca. 5–15 mm long and 5– 12 mm wide, margin coarsely serrate; abaxial surface covered with few pale setae 1.0– 1.5 mm long and very densely covered with glochidiate trichomes 0.25–0.50 mm long, adaxial surface covered with reddish brown setae 2.0– 2.5 mm long, scabrid trichomes 0.50–0.75 mm long and shorter glochidiate trichomes. Flowers in a terminal mono- or dichasia up to 35 cm long overall, with 5–8(–15) deflexed flowers per branch; bracts narrowly ovate, serrate, approximately 5–10(–23) mm long, 2–3(–10) mm wide; pedicels ca. 5–8 mm long; calyx very densely covered with glochidiate trichomes and reddish brown setae, tube conical, 3–4 × 3 mm, calyx lobes ovate-acuminate, ca. 4 mm long, ca. 1.5–2.0 mm wide; petals deeply cymbiform, 8–11 mm long, 3–4 mm deep, bicolourous, distally off-white, proximally blushed with rusty yellow ( Fig. 2 ), base unguiculate and abruptly widened into two small, triangular teeth 2–3 mm from base, densely covered with glochidiate hairs and uniseriate gland-tipped trichomes on back; nectar scales ovate in dorsal view, narrowed above, ca. 4 mm long, ca. 3 mm wide, base incurved, back with two elliptical, confluent nectar sacs at base, these distally red, neck conspicuously thickened, slightly recurved, without filaments, laterally protracted into two small erect wings ca. 1 mm long and 0.5 mm wide; staminodia 2 per scale, ca. 5 mm long, base slightly dilated, filiform above, sparsely papillose to epapillose, white; stamens with filaments 7–9 mm long, white, anthers ca. 0.5 mm long and wide, yellowish brown. Fruit a widely cylindrical capsule with persistent calyx lobes, pedicel erect, ca. 25 mm long, capsule 8–18 mm long and ca. 8 mm wide at apex, densely covered with scabrid and glochidiate hairs 0.5–1.0 mm long, opening with three apical valves; seeds numerous, testa reticulate, black.

Distribution:—The species is so far known only from the Department Amazonas, Province Chachapoyas and the bulk of the collections are from the Utcubamba valley ( Fig. 1 ). The type collection is some 30 km northwest of the town Chachapoyas close to the small village of Caclic. A single record is known from the Marañon valley, where the species was collected on the road between Balsas and Leymebamba, some 40 km south of Chachapoyas. Although herbarium collections are scarce so far, the taxon is likely present in suitable habitats throughout the valleys of the Río Utcubamba and Río Marañón in this region.

Habitat:— Nasa sanchezii is found in open, often disturbed habitats as is typical for many species of Nasa . It has been collected along new road cuttings in fairly dry scree and gravel slopes at elevations of 1400– 2200 m, where it is the only species of the genus (in this region and at this elevation). The collections made by the authors where either along roadsides, or in adjacent dry-shrub forest. The type collections provides no annotations about the habitat.

Affinities:—Although morphological variation within a taxon is sometimes high in Nasa , collections of N. sanchezii are all quite homogenous with only minor differences in diagnostic characters. The taxon is well distinguished from all other species of Nasa by its small flowers with the basally rusty-yellow petals ( Fig. 2 ) and small leaves with typically two triangular leaf lobes on each side ( Fig. 3 ). The collection here chosen as the type collection bears the original determination “ Loasa (Nasa) chenopodiifolia Desr. ”, which is a superficially similar species from Lima and neighbouring departments (Henning & Weigend 2009), however, N. sanchezii differs from that species in its widely branched habit (versus stiffly erect habit), triangular leaf lobes (versus narrowly ovate leaf lobes), much narrower, distinctly clawed and proximally rusty-yellow petals (versus wide, uniformly white petals) and shorter fruits ( Fig. 2 , 3). The affinities of N. sanchezii remain unclear at present.

Etymology:—The species is named in honour of Isidoro Sánchez Vega (Cajamarca, Peru), eminent scholar of the flora of northern Peru.

Additional specimens examined (paratypes): PERU. Dept. Amazonas, Prov. Chachapoyas : Road from Balsas to Leimebamba , 2000 m, M. Weigend, N. Dostert & K. Driessle 97/396 (F, M, NY, USM) . Road from Chachapoyas to Molinopampa , S 06°13´11.5´´ W 077°47´56.8´´, 2200 m, 15 May 2001, T. Henning & C. Schneider 242 (B, HUT, USM) . On road from Tingo to Chachapoyas , roadside, 1800 m, 7 March 1998, N. Dostert 98/45 (CPUN, M, NY, USM,) . Road from Leymebamba to Chachapoyas between Tingo and Chachapoyas, 7 km from Tingo , 1900 m, 5 June 1998, M. Weigend et al. 98/384 (M, NY, USM) . Tingo, betweeen Chachapoyas & Leimebamba, 1900 m, R. Ferreyra 7094 ( MOL, US) . Nogal Cucho, from Balsas towards Chachapoyas , 1830 m, C. P. Cowan et al. 4288 ( NY) . Without precise locality, Chachapoyas , A. Mathews 3002 ( BM, OXF).

Figures

FIGURE 1: Distribution map for the two new species of Nasa.

FIGURE 2: Flowers of Nasa sanchezii. A. Lateral view, note the thin young fruit. B. frontal view.

FIGURE 3: Nasa sanchezii. A. flowering shoot. B. Petal, lateral view. C. Nectar scale, dorsal view. D. Ditto, lateral view. E. Staminode. F. Fruit. Drawn from Henning & Schneider 242. Drawing prepared by S. Kipka (A–E) and T. Henning (F).