Juncus cordobensis

Juncus cordobensis Barros, Lilloa 28: 279. 1957. Type: Argentina. Córdoba: San Justo, Concepción del Tío, 6 nov 1952, A. Castellanos 6675 (holotype LIL 15398; isotype CORD). Fig. 7 Juncus arequipensis Balslev, Brittonia 35: 302. 1983. Type: Peru. Arequipa: Islay, Mollandu, 7 km NE of Matarani, 850 m, 9 Aug 1974, E. López-T. 015 (holotype MO). Perennial, cespitose herbs, 10-30 cm tall. Rhizome horizontal, creeping, 1.5-3 mm diameter, covered by a brushy, filamentous layer of persisting sclerenchyma strands from degraded leaf bases and cataphylls, internodes very short and the culms arising in densely crowded rows. Culms erect, terete, smooth or longitudinally ridged, 0.6-1.1 mm diameter Leaves 2-3 to each culm, all basal, 5-15 cm long, mostly not overtopping the inflorescence; sheaths 1.5-4 cm long with membranous margins terminatiung in two 0.2-0.5 mm long auricles which are scaríous or slightly cartilaginous towards the center; blades linear, flat, 0.8-1.3 mm wide with an adaxial band of hyaline epidermal cells occupying the width of the blade except for the 0.1 mm wide margin. Inflorescence terminal 1.5-3 x 1-2 cm, consisting of 1-5 up to 6-flowered unilateral cymes (drepania); lower inflorescence bract resembling a basal leaf, herbaceous, 1.5-6 cm long, shorter or longer than the inflorescence, upper bracts much smaller, scale like or membranous, each flower clasped by two obtuse ca. 2 mm long membranous bracteoles. Tepals unequal, lanceolate, acuminate, stramineous, with membranous margin, outer ones 5-6 mm long, concave, inner ones 4.5-5 mm long, flat or slightly concave. Stamens six, ca. 2 mm long; filaments filiform; anthers linear, ca. 0.8 mm long. Capsule ellipsoid, acute to obtuse, round to slightly trigonous in cross section, 3.5-4 x 1.5-2.5 mm, ca. 1/5 shorter than the tepals, yellow-brown, unilocular to slightly triseptate. Seeds ellipsoid, apiculate, 0.3-0.4 x ca. 0.2 mm, rugose, castaneous. Distribution and habitat. This species is widespread, occurring in dry areas along the Andes from Colombia to Argentina, and in the lowlands of temperate South America. In Colombia this species has been found in the departments of Cundinamarca and Boyacá, usually above 2700 m. Comments. J. cordobensis is closely related to J. imbricatus and J. capillaceus with which it shares the peculiar feature of a brushy and filamentous cover of sclerenchyma strands that remain on the creeping rhizome when the leaf bases and cataphylls degrade. It differs from J. capillaceus in being more robust and larger in both vegetative and reproductive parts. It differs from J. imbricatus in having: 1) flat leaf blades with an obvious broad band of enlarged hyaline epidermal cells that occupy almost the entire adaxial surface instead of terete or angular blades with only a narrow band of hyaline cells; 2) scarious instead of cartilaginous auricles; 3) the capsule much shorter than the tepals instead of much longer; and 4), the outer tepals 5-6 mm long instead of 4-5 mm long. Representative specimens. Boyacá: Tunja, predios de la UPTC, Guarín-M. 1114 (COL). Cundinamarca: Sopo, Brother Ariste-Joseph s.n., fr (US); San Rafael, Bosa, Jan 1936, García-Barriga 4881, fr (COL); Guasca, 2700 m, V. Grant 7347, fr (US).

Juncus

Sin material de COL

Juncaceae