Juncus breviculmis

Juncus breviculmis Balslev, Brittonia 35: 303. 1983. Type: Venezuela. Merida: páramo at laguna de Mucubaji, near Apartaderos and San Rafael, 35 km NE of Merida, 3800 m, 18 Oct 1953, B. Maguire 39428 (holotype NY). Figs 4, 5 Perennial, soft, cespitose herbs, 10-40 cm tall. Rhizome densely and irregularly branching, ca. 2 mm diameter. Culms erect, 1-20 cm long and always shorter than the leaves, 1-2.5 mm diameter, terete, smooth or with small transverse nodules, sometimes branching in the axils of cauline leaves. Cataphylls absent or inconspicuous. Foliar leaves 1-2 basal and 0-2 cauline to each culm, 6-40 cm long; sheaths 1-6 cm long, membranous towards the margins and terminating in two rounded, 1-2.5 mm long auricles; blades 1.5-2.5 mm diameter, round in cross section but usually flat in pressed specimens, conspicuously transverse-septate. Inflorescence a terminal head or a once to twice branched anthela to 7 x 10 cm with up to seven heads; heads globose, 10 mm diameter and up to 40-flowered when single, or conical, 5 mm diam and only 6-7-flowered in many-headed inflorescences; lower inflorescence bract 4-20 cm long, resembling a cauline leaf, always conspicuously overtopping the inflorescence, sometimes straight, longer than the culm and appearing as a continuation of it except for being cross-septate, sheaths 1-5 cm long, blades 1-2.5 mm diameter, floral bracts lanceolate, acuminate, 2-3 mm long, membranous. Tepals equal, 3-4 mm long, lanceolate, acute, brown to reddish with well marked white membranous margins. Stamens six, ca. 1.5 mm long; filaments filiform, whitish; anthers oblong, ca. 0.5 mm long, yellow. Capsule oblong to obovoid, slightly apiculate and trigonous, 2.3-3 x 1.3-1.6 mm, thin-walled, golden to dark brown. Seeds ellipsoid, apiculate, 0.4-0.5 x ca. 0.2 mm, reticulate, brown. Distribution and habitat. J. breviculmis is distributed in the N Andes from the province of Merida in Venezuela to Colombia. It grows, sometimes submerged, in lakes and streams in the páramos at elevations of 3250-4000 m. According to label information, Cuatrecasas 1557 was growing submerged. In Colombia this species is found in center of the Cordillera Oriental (Santander, Boyacá and Cundinamarca departments), at elevations of 3250-3950 m. Comments. J. breviculmis may be recognized most easily by its short culms, which never lifts the inflorescence above the tip of the foliar leaves. As a result of ecological modifications the length of the culm and the degree of congestion of the inflorescence both vary considerably but in a correlated manner. Thus small plants with culms 1-3 cm long usually have a quite congested inflorescence which often consists of a single 1 x 1 cm head and which terminates the culm; whereas taller plants with culms 15-20 cm long have more open inflorescences up to 7 x 10 cm with several heads, each bearing 6-7 flowers. All intermediates occur. Representative specimens. Boyacá: NW of Belén, stream Minas NE of lake El Alcohol, 3850 m, 29 Feb 1972, Cleef 2061, fl (COL, U); Sierra Nevada del Cocuy, alto Valle Lagunillas, 3915 m, 7 Oct 1972, Cleef 5926, fl (COL, U); páramo de la Rusia, NW-N de Duitama, 3565 m, 6 Dec 1972, Cleef 6740, fl (COL); 3570 m, 13 Dec 1972, Cleef 7136A, fl (COL). Cundinamarca: Planos de Toldadero, 3950 m, 13 Sep 1938, Cuatrecasas 1557, fl (COL, F, US); páramo de Monserrate, El Granizo, 3250 m, 8 Feb 1986, Fernández-Alonso 5149, fr (COL); Bogotá, localidad 20, PNN Sumapaz, alrededores de lagunas Chisacá, Larga y del Rebosadero, 3700-3950 m, 15 Oct 1999, Pedraza 723 (COL); páramo de Guargua, Pantano Largo, 3610 m, 2 May 1987, R. Sánchez 98, fl (COL); páramo de Chisacá, 3500 m, 3 Jun 1987, R. Sánchez 139, fl (COL). Santander: páramo del Almorzadero, 3600-3800 m, 28 Nov 1941, Cuatrecasas 13509, fl (COL, US); N of Cerrito, 31 Oct 1944, Fassett 25999, fl (NY, UC, US); páramo de Santurbán, 3600 m, 27 Aug 1948, Araque-Molina 18S722, fr (US).

Juncus

Cleef 2061
Cleef 5926
Cuatrecasas 1557
Fernández 5149
Pedraza 723
Sánchez 98
Sánchez 139
Cuatrecasas 13509

Juncaceae