Juncus tenuis

Juncus tenuis Willd., Sp. Pl. 2: 214. 1799. Type: USA. ‘America boreali,’ collector unknow (lectotype B-Willd; isolectotypes B-Willd, HBG, NY, fide H. Balslev Fl. Netrop. Monog. 68: 79. 1996). Figs. 11, 19 Perennial, cespitose herbs to 60 cm tall. Rhizome densely branching. Culms smooth or sometimes slightly longitudinally ridged; auricles 0.5-1.5 mm long, usually longer than wide, rounded, thin, scaríous. Leaf blades flat, adaxial side with a band of hyaline cells occupying 3/4 or more of the width, only the margins with dense, chlorophyll filled cells. Inflorescence composed of several few-flowered, unilateral cymes, the branching is irregular and the inflorescence is not equally dense throughout, and relatively long, flower-free branch segments alternate with more clustered sections; lower inflorescence bract similar to basal leaves, distal ones gradually shorter. Tepals recurving apically towards maturity. Capsule shorter than the tepals when mature, thin walled, the valves not recurved along the seams and the capsule therefore not 3-keeled. Distribution and habitat. J. tenuis is a widespread and common species in North America and introduced to western Europe in the 19th century where it is now widespread and still extending its range. In the Neotropical region this species is found throughout the highlands. It occurs throughout the Mexican and Central American highlands, on Jamaica and Puerto Rico, and in the Andes from Venezuela to Ecuador and Argentina. It is weedy and typically anthropochorous, commonly found at elevations of 1000-3000 m above sea level, along roads and in places where the soil is disturbed and wet from seeping water. In Colombia J. tenuis is widely distributed across the center of the Andean region, and two collection in south (Cauca and Putumayo), between 1300 and 2850 m. The dispersal is facilitated by the ability of the outer seed coat to swell up to become a sticky, gelatinous cover that adheres to passers-by. Comments. Balslev (1996), in the Flora Neotropica treatment recognized three varieties of Juncus tenuis, two of which were found in Colombia (J. tenuis var. tenuis and J. tenuis var. platycaulos). However, Kirschner et al. (2002c) elevated these varities to independent species and this treatment follows this proposal. Representative specimens. Antioquia: Bello, 1500 1800 m, 17 Jun 1930, Archer 182 (US); 3 km above Nariño on road to Sonsón, rio Samana, 2130-2800 m, 24-25 May 1944, Ewan 15719, fl (US); Facultad de Agronomia, Medellin, 1560 m, 10 Jul 1947, Hedge 6938, fr (US); Frontino, Nutibara, rio Cuevas, 2000 m, 14 Jul 1987, P. Sánchez 1402, fr (COL); Frontino, Nutibara-Murri road km 13, 1925 m, 23 Sep 1987, Zarucchi 5689, fl (COL, MO, NY). Boyacá: Tunja, 2820 m, Aug 1973, Ballesteros-G. 36, fl (COL); rio Pómeca valley 20 km NW of Arcabuco, 2280 m, 20 Aug 1944, Fassett 25632, fr (COL, US); Arcabuco, vereda Peñas Blancas, hacienda Las Delicias, 2600 m, 11 May 1996, Fernández-Alonso 14154, fr (COL); Pajarito, Corinto, Chorro road, 1600 m, 22 Jun 1988, G. Sánchez 63, fr (COL); Santa Maria, sender ecológico Hyca-Quye, carretera Santa Maria-Bogotá, 1000 1200 m, 20 May 2009, A. Zuluaga 469 (COL). Cauca: above Carpenteria, E slope of Cordillera Occidental, 2500 m, 23 Apr 1939, Alston 8227 (NY). Chocó: Bolivar- Quibdó road, km 126, 1460 m, 13 Apr 1983, Croat 55881 (MO). Cundinamarca: Sabana de Bogotá, 2600 m, 29 Dec 1938, Cuatrecasas 475, fl, fr (COL, US); San Bernardo, vereda Santa Marta, quebrada La Chorrera, 2300-2350 m, 20 Jul 1981, Díaz-Piedrahita 2998, fl (COL); Bogotá, Ciudad Universitaria, May 1941, García-Barriga 10012, fl (COL); Albán, Oct 1932, Pérez-Arbeláez 2207, fr (COL, US); Quetame, rio Saname, 1450 m, 11 Feb 1960, Uribe-Uribe 3613, fr (COL). Putumayo: Valle de Sibundoy, 2200 m, 7 May 1963, Bristol 937, fr (GH, COL). Quindío: Cocora Natural Park, La Cascada, 2750 m, 10 May 1990, Franco-Roselli 3157, fl (COL); Salento, 2100-2500 m, 25-31 Jul 1922, Pennell 8879, fr (GH, K, NY, PH, US). Risaralda: municipio Pereira, Parque Natural Regional Ucumari, entre La Pastora y Peña Bonita, 2300-2600 m, 22 Nov 1989, G. Galeano 2139, fl (COL). Norte de Santander: Sarare, 1300 m, 13 Oct 1941, Cuatrecasas 12115, fr (COL, F); rio Colorado confluence near rio Valegra, Chitaga, 1845 m, 15 Nov 1942, Fosberg 19107, fr (COL, US). Santander: Charala, veredas EI Taladro and Bogotacito, 2100-2300 m, 7 Dec 1978, Díaz-Piedrahita 1678A, fr (COL); 5 km SW of La Paz towards Vélez, 2220 m, 27 Apr 1944, Fasset 25150, fr (NY, US); 5 km N of La Paz and 25 km NE of Vélez, 1900 m, 5 May 1944, Fasset 25176, fr (NY, UC, US, WIS); río Minero valley near Florian, 1850 m, 24 Sep 1944, Fassett 25786, fr (COL, US), Fassett 25787, fr (US, COL). Tolima: Toche, 2500 m, 25 May 1942, von Sneidern 3132, fr (GH, NY, US). Valle del Cauca: hoya del río Bugalagrande, loma de Barragán, desde La Parilla a La Machuca, 2660-2750 m, 13 Apr 1946, Cuatrecasas 20651, fl, fr (F, US), Cuatrecasas 20674, fl (F, US); Carrizales N of Las Brisas, 2200 m, 25 Oct 1946, Cuatrecasas 22543, fl (F, US). Locality unknow: Mutis 3736, fr (US), Mutis 6191, fl (US).

Juncus

Sánchez 1402
Zarucchi 5689
Fernández 14154
Sánchez 63
Zuluaga 469
Díaz 2998
García 10012
Pérez 2207
Uribe 3613
Bristol 937
Franco 3157
Galeano 2139
Cuatrecasas 12115
Fosberg 19107
Fassett 25786
Fassett 25786

Juncaceae