Juncus capillaceus Lam.

• Authority

  Balslev, Henrik. 1996. Juncaceae. Fl. Neotrop. Monogr. 68: 1-167. (Published by NYBG Press)

• Family

  Juncaceae

• Scientific Name

  Juncus capillaceus Lam.

• Type

  Type. Uruguay. Montevideo, Commerson s.n. (holotype, P!; isotypes, B-W 6848!, MO!, P!, W!).

• Synonyms

  Juncus tenuifolius Steud., Juncus capillaceus var. montevidensis Buchenau

• Description

  Species Description - Perennial, cespitose herbs, 5-30 cm tall. Rhizome creeping, 1.5-2 mm diam., covered with a filamentous dark brown layer of remaining sclerenchyma strands from splitting leaf bases and cataphylls, internodes very short and the culms arising in dense rows. Culms erect, canaliculate, 0.4-0.7 mm diam. Cataphylls 1-3 to each culm, to 1.5 cm long, yellowish brown, with a rudimentary blade to 5 mm long. Foliar leaves all basal, 1-2 to each culm, 5-20 cm long; sheaths 0.7-1.7 cm long with the margins terminating in two 0.3 mm long, rounded auricles; blades filiform, 0.3-0.6 mm diam., obtuse-angled with an adaxial groove at the base. Inflorescence terminal or pseudolateral, compound, 2-10-flowered, consisting of 2-3 short, unilateral cymes (drep-ania). Lower inflorescence bract 1.5-5 cm long, appearing as a continuation of the culm and exceeding the inflorescence, upper bracts progressively shorter, the ultimate ones scariose, to 3 mm long. Each flower clasped by two 1 mm long bracteoles. Tepals unequal, lanceolate, light green with scariose margins, turning brown to stramineous at fruit ripening, outer tepals 2.3-3 mm long, inner tepals 2-2.5 mm long. Stamens 6, 1.1-1.3 mm long; anthers oblong, 0.3-0.4 mm long. Capsule ellipsoid, to oblong, apiculate or often becoming truncate toward dehiscence, trigonous with concave sides, 2.3-2.6 x 1.2-1.6 mm, brown, glossy at maturity, thin walled and often with impressions of the contained seeds, 3-septate. Seeds ovoid, asymmetrical, slightly apiculate, 0.4-0.6 x 0.3-0.4 mm, finely patterned by narrow, transversally arranged polygons, brown.

• Discussion

  Distribution and Ecology: Juncus capillaceus grows at high elevations, usually above 2700 m along the Andes from Venezuela to Ecuador and Bolivia; it is rare in Peru. It also occurs at low elevations in Concepcion in Chile and along the E coast of South America from Rio de Janeiro in Brazil to Buenos Aires in Argentina. There are scattered occurrences in Spain (Silva Pando, 1987), South Africa (Adamson, 1935), and Australia (Beadle et al., 1972) that presumably represent recent introductions, since the plants are ruderal there. At least in the N Andes, where I have observed it, it is ecologically similar to J. imbricatus and grows and flowers in dry hard soils, and the two species are often seen together. It is found in small clumps along roads or in old grass fields.

• Distribution

  Colombia South America| Boyacá Colombia South America| Cundinamarca Colombia South America| Norte de Santander Colombia South America| Nariño Colombia South America| Valle Colombia South America| Mérida Venezuela South America| Ecuador South America| Azuay Ecuador South America| Cotopaxi Ecuador South America| Loja Ecuador South America| Pichincha Ecuador South America| Tungurahua Ecuador South America| Peru South America| Cajamarca Peru South America| Brazil South America| Rio de Janeiro Brazil South America| Bolivia South America| Cochabamba Bolivia South America|