46. Burmeistera rostrata Jeppesen, Flora of Ecuador 14: 25. 1981.

Type:— COLOMBIA. Putumayo: El Mirador, “circa 50 kms generally east of San Francisco”, 2100 m, 15 Aug 1965 (fl, fr), R. King & A. Guevara 6180 (holotype: F! [F0052930 F]; isotypes: COL! [COL000115338], NY! [NY00468008], US! [US01105613]). Figs. 23, 24A–E .

Scandent herbs up to 1 m tall. Young stems puberulous, later glabrous. Petiole 4–15 mm long, glabrous to sparsely puberulous; blade narrowly elliptic, elliptic, narrowly ovate or ovate, 6–11 × 1.0–3.5 (–6.0) cm, sometimes the distal third falcate, glabrous except for some trichomes in primary and secondary veins above, puberulous along the veins beneath, base usually asymmetric, cuneate, apex acute to acuminate, margin irregularly sinuous to toothed, with 8 to 13 extramarginal hydathodes per side (1–4 per centimeter), secondary veins 10 to 16 per side, inconspicuous, intramarginal vein present. Subtending leaves often reduced to 2–5 × 0.4–0.8 cm. Peduncle 2.6–3.0 cm long, glabrous, ebracteolate. Hypanthium globose, 3–4 × 3–4 mm, glabrous to sparsely puberulous. Calyx lobes ovate, 1.5–2.5 × 0.5–1.0 mm, ascending, glabrous, basally spaced by sinuses up to 1 mm wide, margin with one tooth per side, apex obtuse. Corolla green suffused with purple, glabrescent to sparsely puberulous; tube 0.8–1.8 cm long, ca. 1.5 mm in diameter at its mid- and distal portions, slightly inflated proximally up to 4 mm diameter; lobes very narrowly ovate, not falcate, forming a sharp rostrum oriented at a straight line with the tube during preanthesis, apex caudate; dorsal lobes 7–9 × 0.6–1.0 mm, lateral lobes 6–7 × 0.5–1.0 mm, ventral lobe 5.0–6.5 × 0.5–1.0 mm. Synandrium 1.0‒ 1.7 cm long, exserted up to 4 mm; filament tube 6–12 mm long; anther tube 4–5 mm long, glabrous except for the barbate ventral anthers that have an apical tuft of white trichomes. Berries globose, 9–14 × 10–14 mm, inflated, glabrous or glabrescent, fuchsia.

Phenology: — Burmeistera rostrata has been collected with flowers and fruits in January, February, April to June, August, September, November and December.

Distribution, ecology and conservation status: — Burmeistera rostrata is restricted to the southern Andes of Colombia. It occurs in cloud forests of the eastern Andean slopes of the departments of Nariño and Putumayo, and in the Western Cordillera, in the department of Valle del Cauca, at elevations between 1350 and 2800 m. Following the IUCN´s (2022) criteria [B1(EOO) and B2(AOO), conditions (a) and (b), and C2(a)(i)], this species qualifies as Critically Endangered.

Notes: — Burmeistera rostrata is unique in having the leaf blade usually narrowly lanceolate to narrowly ovate, sometimes falcate, the preanthetic corolla straight, rostrate, the corolla lobes very narrowly triangular, with caudate apices, and the berries small, 9‒14 × 10‒14 mm. The species is similar to B. salicifolia, B. villosa and B. xerampelina, from which it differs by the corolla with caudate and very narrowly ovate lobes that form a sharp rostrum aligned at 180° with the tube during preanthesis, the dorsal lobes 7–9 × 0.6–1.0 mm, the lateral lobes 6–7 × 0.5–1.0 mm, and the ventral lobe 5.0–6.5 × 0.5–1.0 mm; and by the synandrium exserted up to 4 mm (versus corollas with narrowly ovate lobes that form an angle of 90–120° with respect to the tube at preanthesis, these with acute to shortly acuminate apex; dorsal lobes 10–35 × 2–5 mm; lateral lobes 10–23 × 1–5 mm; and ventral lobe 10–22 × 2–5 mm; and by the synandrium exserted up to 5–8 mm in the remaining species).

Additional specimens examined:— Nariño. Ipiales, carretera de la Victoria a San Jorge “El Hospital”, 2100 m, 23 Jun 1962 (fl, fr), L. Mora 2155 (COL, PSO) ; San Francisco, Carretera Pasto-Mocoa, entre el Mirador y San Francisco, 1500‒2200 m, 27 Nov 1967 (fl), L. Mora 4453 (COL) ; Ipiales, corregimiento de La Victoria, Río San Francisco, Río Manizales, 2400 m, 15 Apr 1992 (fl, fr), B. Ramírez 4781 (PSO, NY). Putumayo. Mocoa, cercanías de El Mirador, 1800 m, 14 Apr 1988 (fl, fr), O. de Benavides 9514 (PSO) ; Valle del Sibundoy, ca. 8 km N Sibundoy, 2650 m, 18 Apr 1963 (fl, fr), M. Bristol 828 (GH) ; along road between Pasto and Mocoa, in vicinity of Mirador, 1800 m, 3 Dec 1980 (fl, fr), T. Croat 51802 (COL) ; Villa Garzón, carretera a Puerto Asís, 1350 m, 76º34´W, 1º10´N, 3–5 May 1994 (fr), J. Fernández et al. 11409 (COL, NY) ; Cordillera de Los Andes, vertiente oriental, entre San Francisco y Mocoa, El Mirador, 2130 m, 5 Jan 1957 (fl, fr), J. Idrobo et al. 2367 (COAH, COL) ; highway between Sibundoy and Mocoa between km 90‒91, 2500 m, 26 Jan 1976 (fl, fr), J. L. Luteyn et al. 5049 (COL) ; entre Mocoa y Sibundoy, km 112‒113, 2240 m, 28 Jun 1976 (fl, fr), J. L. Luteyn et al. 5066 (NY) ; San Francisco, carretera San Francisco-Mocoa, 2700‒2800 m, 23 Sep 1972 (fl, fr), L. Mora et al. 6157 (PSO) ; Mocoa, km 112 Pasto-Mocoa, Murallas, El Mirador, 1°08´N, 76°45´W, 2100 m, 31 Aug 1995 (fl, fr), B. Ramírez et al. 8508 (PSO) ; Colón, Reserva Natural La Rejoya, 1°18´N, 76°52´W, 2750 m, 10 Nov 1996 (fl, fr), B. Ramírez 10178 (PSO) ; El Mirador, Excursion (bei Mocoa) 01 Jan 1965, (fl, fr), “Herb. W. Schwabe” s.n. (B). Valle del Cauca. Hacienda Tokio, ca. 10 km S of Queremal, 3º30´N, 76º42´W, 2000 m, 26 Feb 1983 (fl), A. Gentry et al. 40848 (COL).