Juncus pallescens

Juncus pallescens Lam., Encycl. 3: 268. 1789. Type: Argentina. Buenos Aires: 1767, P. Commerson s.n. (holotype P; isotype P). Figs. 15, 16 Perennial, cespitose herbs, 20-35 cm tall. Rhizome densely branching, 1.5 mm diameter, with few, small, scariose scales. Culms erect, 0.8-1.5 mm diameter, terete, smooth. Cataphylls 0-2 to each culm, to 4 cm long, inconspicuous. Foliar leaves 2-3 basal and 0-1 cauline to each culm, 10-16 cm long; sheaths 2-7 cm long with scariose margins terminating in two 1.5-3.5 mm long, rounded auricles; blades 1.5-2 mm diameter, round to elliptic in cross section, septate but sometimes inconspicuously so. Inflorescence decompound, anthelate, 1.5-10 x 1.5-4 cm, flower heads (1-)3-4, globose at maturity, 0.5-1 cm diameter, (4-)8-20 flowered, castaneous, ultimate head bearing branches more than 0.45 mm diameter; lower inflorescence bract 1-3 cm long, shorter than the inflorescence, resembling foliar leaves or scalelike; distal bracts shorter; floral bracts acuminate, ca. 3 mm long, scaríose, whitish, usually contrasting the tepal color. Tepals subequal, 3-4.5 mm long, lanceolate, acuminate, robust, rigid, outer tepals concave and scaríose towards the margin, inner tepals flat with distinct scaríose margin. Stamens usually 6 or rarely 3, 1-2 mm long; anthers 0.5-0.9 mm long, usually about 1/2 as long as the filaments. Capsule ellipsoid to obovoid, truncate to bluntly acute, 3-lobed to trigonous, (2.2-)2.5-3 x 1.2-1.3(-1.6) mm, green at the base, brown at the apex, glossy, unilocular. Seeds broadly ellipsoid, conspicuously apiculate, 0.3-0.4 x ca. 0.2 mm, reticulate, yellowish brown with a hyaline outer seed coat. Distribution and habitat. J. pallescens occurs in the Andes from southern Colombia to S Chile and in E South America from Rio Grande do Sul in Brazil to Buenos Aires in Argentina. In Colombia, Ecuador, Peru, and Bolivia it grows at elevations of 1900-3600 m, often in disturbed areas but also in natural Sphagnum bogs and edges of páramo lakes. In Colombia this species is known from a single collection made in the nariño department. Material examined. Nariño: municipio de Pasto, Torobaje, Predios de la ciudad universitaria, 2530 m, 25 Sep 1985, Ramírez-P. 353, fl (COL).

Juncus

Ramírez 353

Juncaceae