Two New Species of Palicourea (Rubiaceae) from Western South America

Abstract

The new species Palicourea jatunsachensis and P. plowmannii are similar vegetatively to P. subspicata, but can be separated by linear relatively long calyx lobes and well-developed inflorescence bracts, respectively. The neotropical genus Palicourea Aublet comprises about 200 species of shrubs, small trees, and suffrutescent herbs found widely in moist to wet forest. It is closely related to Psychotria subg. Heteropsychotria Steyermark, from which it is separated by its corollas that are generally relatively longer and tubular to infundibuliform and have a basal swelling that is closed at the top by a ring of dense pubescence borne on the inside of the corolla. Additionally, the inflorescences are characteristically brightly colored and the corollas are often strongly gibbous and asymmetrical at the apex, but these features vary widely within the genus (Taylor, 1989). Palicourea jatun-sachensis C. M. Taylor, sp. nov. TYPE: Ecuador. Prov. Napo: Cant6n Tena, Estaci6n Biologica Jatun Sacha, ca. 8 km ESE of Puerto Misahualli, 1?04'S, 77?37'W, J. S. Miller & Medical Botany Class 2167 (holotype, MO). Figure 1A, B. A Palicourea subspicata Huber panicula breviore purpurea violaceave etiam bracteis inflorescentiae sicut lobulis calycinis linearibus longioribus differt. Suffrutescent herbs or shrubs to 2.5 m tall, flowering at 0.3 m; stems glabrous. Leaves paired, with blades 20-33 cm long, 8.5-16 cm wide, 1.6-2.4 times as long as wide, elliptic, at apex acuminate with tip 5-20 mm long, at base cuneate to obtuse, papyraceous to thinly chartaceous, sparsely to usually densely pustulose abaxially but otherwise glabrous; secondary veins 14-17 pairs, widely spreading, broadly curved, sometimes looping to interconnect near apex, without domatia, costa and secondary veins usually prominulous above and below, occasionally with 1(-2) weakly developed intersecondary veins present between pairs of secondary veins; petioles 30-57 mm long, glabrous; stipules united to form a continuous sheath, glabrous; sheath 1-3 mm long, interpetiolar sinus concave to usually truncate; lobes 6-17 mm long, lanceolate to ovate, acute, usually deciduous after distalmost 1-2 nodes. Inflorescences racemiform, narrowly cylindrical; peduncles 3.5-14 cm long; panicles 1.5-4.5 cm long, 1.5-4 cm wide, 0.9-1.8 times as long as wide, with flowers borne in congested cymules of 3-5; axis somewhat thickened; bracts 3-10 mm long, linear, acute; pedicels 0-1.5 mm long, thickened; peduncle, axis, branches, bracts, and pedicels minutely puberulous, purple or violet; flowers with calyx puberulous to usually glabrescent, purple to violet; hypanthium cylindrical, 1-1.2 mm long; limb 1.5-5.5 mm long, divided to base, lobes narrowly triangular to linear, acute; corolla red, sometimes tinged with yellow or yellow internally, membranaceous, tubular to somewhat funnelform, somewhat swollen at base, generally straight in tube, externally densely puberulous with stout multicellular trichomes ca. 0.1 mm long, internally glabrous except for a ring of villous pubescence just above the basal swelling; tube 11-15 mm long; lobes 12 mm long, triangular. Infructescences similar in size, proportion, and color to inflorescences, with fruiting pedicels 2-10 mm long; fruit ca. 5 mm long, ca. 8.5 mm wide, didymous, the halves subglobose, laterally somewhat flattened, purple; pyrenes with 3-5 gently angled faces. Uncommon in understory of wet primary forest at 280-400 m in Amazonian Colombia and Ecuador. Collected in flower February-August and October, in fruit January, April, and July. This species is distinguished by its relatively large leaves, narrow racemiform inflorescences, narrowly triangular to linear bracts, long narrow calyx lobes, and didymous fruits with gently angled pyrenes. The stipules deciduous after the distalmost 1-2 nodes represent an unusual condition in Palicourea. This new species is simlar to P. subspicata Huber, which can be distinguished by its inflorescences with long panicles, 6.5-23 cm long, calyx limb shorter, ca. 0.8 mm long, and pyrenes smooth. The specific epithet refers to the Jatun Sacha Biological Station, where most of the specimens of this species have been collected. NOVON 4: 55-57. 1994. This content downloaded from 157.55.39.30 on Thu, 26 May 2016 05:00:49 UTC All use subject to http://about.jstor.org/terms