New Species of Gibsoniothamnus (Bignoniaceae: Schlegelieae)

Abstract

Three new species of Gibsoniothamnus L. O. Williams, G. grandiflorus, G. stellatus, and G. versicolor, are described as new. Gibsoniothamnus L. O. Williams is a genus of about 14 species of epiphytic shrubs, variously classified in the Bignoniaceae or Scrophulariaceae. This unusual group of Central American epiphytes is most closely related to the neotropical genus Schlegelia Miquel, currently classified in the Bignoniaceae tribe Schlegelieae. Undescribed species have been filed with both Scrophulariaceae and Bignoniaceae, so a collaborative project was begun to identify and describe the new species. Collaborative work was cut short by the untimely death of Al Gentry. The following species were discovered during the study. Gibsoniothamnus grandiflorus A. Gentry & Barringer, sp. nov. TYPE: Panama. Veraguas: ridge of Cordillera de Tute along trail to Cerro Tute, ca. 3-4 km past Escuela Agricola Alto de Piedra, just W of Santa Fe, 8032'N, 81007'W, 20 Mar. 1982, Knapp & Kress 4389 (holotype, MO; isotype, PMA). Figure 1. Species floribus grandis, a Gibsoniothamno truncato lobis calyce triangulatis longe acuminatis, pedicellis longioribus differt. Epiphytic shrub to 3 m tall; bark gray-brown; stems angled, glabrous, to 5 mm diam., with raised leaf bases at the nodes. Leaves opposite, subequal to equal across the node; petioles 5-14 mm long, glabrous or sparsely pubescent; blade ovate to obovate or lanceolate, 6.5-14.5 cm long, 3.0-6.2 cm wide, coriaceous, glabrous, shiny above, the base cuneate, the apex acuminate, secondary veins 3 or 4 per side, impressed above, prominent below, glandular pits in fields between the veins below, pocket domatia occasionally present in the axils of the midvein and secondary veins toward the base of the blade. Flowers in congested, axillary panicles; primary peduncle to 1.5 cm long; bracts narrowly triangulate, 3-5 mm long, pubescent; the secondary peduncles to 7 mm long; bracteoles to 3 mm long, ovate, acuminate; pedicels 2.5-3.5 cm long, thicker above; calyx funnelform, the tube 5-9 mm long, red to red-purple, the lobes narrowly triangulate, unequal, 7-13 mm long, long-acuminate, glabrous to minutely ciliate; corolla cylindric, slightly ampliate above, 3.5-4.0 cm long, 6-7 mm diam., reddish pink to red, fleshy, the upper lobes rounded, 3-4 mm long and wide, the lateral lobes rounded to ligulate, 4-5 mm long, 4 mm wide, the median lobe ligulate, 4-6 mm long, 3-4 mm wide; stamens attached 6-9 mm from the base of the corolla tube, filaments 20-26 mm long, glabrous; staminode 1020 mm long, filiform, the apex clavate; pistil glabrous, the ovary globose to oblate, 2-3 mm diam., the style 30 mm long, the stigma slightly bilobed. Berry globose, 8-10 mm diam., green. This species is most easily distinguished by its large, slightly ampliate flowers. It appears to be most closely related to Gibsoniothamnus truncatus and G. latidentatus. It differs from G. truncatus by its larger, ampliate corollas, pedicels more than 2 cm long, and narrowly triangulate calyx lobes. It differs from G. latidentatus by its corollas more than 3 cm long, reddish calyx, short staminode, and calyx lobes 7-13 mm long. This species has an interesting disjunct distribution: the plants from Panama, collected along the El Llano-Carti road, have narrower, more acuminate leaves than those from Cocle, mostly collected on Cerro Tute. Paratypes. PANAMA. Cocle: vicinity of Escuela Agricola Alto de Piedra, 3200-3400 ft., 3 Apr. 1980, Antonio 3961 (MO); about 16 km NW of Santa Fe on descent to Rio Caloveborita, 650 m, 4 Sep. 1975, Dressler 5142 (MO); near third branch of Rio Santa Maria, 10-14 km NW of Santa Fe, 650-750 m, 10-11 Oct. 1975, Dressler 5171 (MO); shoulder of Cerro Tute, 25 May 1977, Folsom & Edwards 3345 (MO); ridge of Cerro Tute, along trail to Cerro Tute, 3-4 km past Escuela Agricola Alto de Piedra, 8?32'N, 81?07'W, 800-1400 m, 20 Mar. 1982, Knapp & Kress 4363 (MO); Cerro Tute, E slopes, 1 km beyond Escuela Agricola Alto Piedra NovoN 5:120-124. 1995. This content downloaded from 207.46.13.164 on Sun, 26 Jun 2016 06:32:05 UTC All use subject to http://about.jstor.org/terms Volume 5, Number 2 Barringer & Gentry 121 1995 New Species of Gibsoniothamnus