Juncus imbricatus Laharpe

  • Authority

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

  • Family

    Juncaceae

  • Scientific Name

    Juncus imbricatus Laharpe

  • Type

    Type. Argentina.  Buenos-Ayres, Commerson s.n. (syntype, n.v.); Chile. Concepción, M. Lesson s.n. (syntype, K!).

  • Synonyms

    Juncus chamissonis Kunth, Juncus imbricatus var. chamissonis (Kunth) Buchenau, Juncus spanianthus Steud., Juncus collinus Steud., Juncus multiflorus Ehrh., Juncus lechleri Steud., Juncus imbricatus var. lechleri (Steud.) Buchenau, Juncus urvillei Steud., Juncus capillaceus var. chilensis Buchenau, Juncus pringlei Fernald

  • Description

    Species Description - Perennial cespitose herbs, 15-45 cm tall. Rhizome creeping, 2-3 mm diam., covered with a filamentous dark brown layer of sclerenchyma strands that remain from disintegrating old cataphylls and leaf bases; internodes very short and the culms arising in densely crowded rows. Culms erect, canaliculate, 0.5-1.5 (-1.8) mm diam. Cataphylls 3-4 to each culm, to 5 cm long, dark brown or upper ones sometimes yellowish brown or light green, with a rudimentary blade to 5 mm long. Blade-bearing leaves all basal, 1-2 to each culm, 10-35 cm long; sheaths 1.5-6 cm long with scariose margins terminating in two 0.3-0.5 mm long auricles; blades filiform, 0.6-1 mm diam., canaliculate and obtuse-angled, with an adaxial basal groove. Inflorescence terminal, compound, 1-30-flowered, consisting of (1-)2-4, clustered, unilateral cymes (drepania). Lower inflorescence bract resembling a basal leaf, herbaceous, to 8 cm long and exceeding the inflorescence, or shorter than the inflorescence and acicular, distal bracts progressively shorter, the ultimate ones scariose, to 3 mm long. Each flower clasped by two 1.5-2 mm long bracteoles. Tepals unequal, lanceolate, midrib green, turning brown, margins castaneous, scariose at fruit ripening, outer tepals 3.5-5 mm long, inner tepals 3-4 mm long. Stamens 6, 1.7-2.1 mm long; anthers linear, 0.8-1 mm long. Capsule ellipsoid, apically obtuse to truncate, trigonous with somewhat concave sides, 3.5-5 x 1.8-2.5 mm, castaneous, glossy at maturity, thick walled and not showing impressions of the contained seeds, 3-septate. Seeds broadly ovoid, asymmetrical, slightly apiculate, 0.4-0.6 x 0.2-0.3 mm, rugose, brown.

  • Discussion

    Juncus imbricatus is most closely related to J. capillaceus, with which it shares the feature of a brushlike cover of splitting leaf sheaths and cataphylls on the creeping rhizome. The two species are similar in several other respects, but are always distinct through the larger dimensions of J. imbricatus in both vegetative and reproductive structures, especially the size of the capsule (3.5-5 mm vs. 2.3-2.6 mm long). It is remarkable that these two species are sympatric throughout their areas, including South Africa and Australia, where they are introduced.

    Distribution and Ecology: Juncus imbricatus is a mainly South American species occurring in the Andes from Colombia to N Argentina, in Concepción in Chile, and in E South America in Corrientes in Argentina, in Uruguay, and in the highlands S of Buenos Aires. It also occurs disjunctly in Mexico, in the Cape Province of South Africa (Adamson, 1935, as J. chamissonis), in Australia (Beadle et al., 1972), and in Portugal (Snogerup, 1980; Fernández-Carvajal, 1981-1982), where it presumably is recently introduced since the plants are ruderal there. In the Andes of Ecuador, Peru, and Bolivia, I often observed it as a weed on roadsides and in abandoned fields at elevations of 2500-3800 m. Together with J. capillaceus it is unusual in the genus because it often grows and flowers in very dry habitats where the soil may be completely hardened. In Argentina and Uruguay it occurs at lower elevations.

  • Common Names

    Kuchi much’u, kuchi, much’u

  • Distribution

    Mexico North America| Hidalgo Mexico North America| México Mexico North America| Oaxaca Mexico North America| Tlaxcala Mexico North America| Veracruz Mexico North America| Colombia South America| Boyacá Colombia South America| Cundinamarca Colombia South America| Valle Colombia South America| Ecuador South America| Azuay Ecuador South America| Bolívar Ecuador South America| Cañar Ecuador South America| Chimborazo Ecuador South America| Cotopaxi Ecuador South America| El Oro Ecuador South America| Imbabura Ecuador South America| Loja Ecuador South America| Pichincha Ecuador South America| Tungurahua Ecuador South America| Peru South America| Ancash Peru South America| Apurímac Peru South America| Cajamarca Peru South America| Cusco Peru South America| Huancavelica Peru South America| Junín Peru South America| La Libertad Peru South America| Lima Peru South America| Puno Peru South America| Bolivia South America| Chuquisaca Bolivia South America| Cochabamba Bolivia South America| La Paz Bolivia South America| Tarija Bolivia South America| Argentina South America| Salta Argentina South America|