Two New Species of Weinmannia (Cunoniaceae) from the Venezuelan Guayana

Abstract

Two new species of Weinmannia (Cunoniaceae) from the highlands of southern Venezuela are described and illustrated. Weinmannia ilutepuiensis P. E. Berry & J. Bradford is a simpleleaved, serrate-margined species known only from IhI-tepui in Estado Bolivar, and Weinmannia corocoroensis J. Bradford & P. E. Berry is a pinnateleaved species with tiny, revolute-margined leaflets currently known only from Cerro Coro Coro in Estado Amazonas. While preparing the floristic treatment of Cunoniaceae for the Flora of the Venezuelan Guayana and as part of a broader study of neotropical Weinmannia by the second author, two distinctive new species of Weinmannia were found among the collections examined from the tepuis, or tabletop mountains, of southern Venezuela. Both species were collected from relatively poorly explored mountains, one from I1l-tepui in Estado Bolivar, and the other from Cerro Coro Coro in Estado Amazonas. These species are described and illustrated below. Weinmannia ilutepuiensis P. E. Berry & J. Bradford, sp. nov. TYPE: Venezuela. Estado Bolivar: I1h-tepui, lower plateau, with varied habitats, rocky, boggy, and short forest to 5 m tall, 05025'03N, 60?29'W, 2500 m, 16 Apr. 1988, Liesner 23413 (holotype, MO; isotypes, NY, US, VEN). Figure 1A-D. Frutex vel arbor 1-5(10)-metralis, foliis simplicibus, laminis foliorum infra dense ochraceo-lanatis, ellipticis, coriaceis, marginibus serratis, 1.5-6.0 x 0.8-3.5 cm; pseudoracemis 4-6 cm longis, lanatis, pedicellis sub anthesi 1-2.5 mm longis post anthesin 2.5-4 mm longis; capsulis villoso-lanatis, 3-3.5 mm longis. Shrub or small tree 1-5(-10) m tall; young stems lanate, nodes hirsute. Leaves opposite, simple, elliptical, subcoriaceous, 1.5-6.0 cm long, 0.8-3.5 cm wide, broadly acute to rounded at the apex, broadly acute at the base, sparsely pilose to glabrescent and dark green on the upper surface, light brown and densely lanate-villous on the lower surface; secondary veins 10-15 per side, impressed on the upper surface and prominent on lower surface, subparallel from midvein until divaricating within ca. 4 mm of the margin with each branch joining an adjacent branch at a marginal sinus; margins serrate, planar to revolute, with 10-15 glandular teeth per side between successive sinuses or adjacent to a sinus; petioles 3-4 mm long, lanate; stipules broadly elliptical to suborbicular, 3-6 mm long, 3-5 mm wide, hirsute on the outside, dark brown and glabrous adaxially. Pseudoracemes in pairs at the branch apex, exceeding the leaves, 4-6 cm long, axis lanate. Flowers arranged in fascicles along the inflorescence axis with 1-several flowers per fascicle; bracteoles subtending fascicles, linear to obovate, 1.5-2 mm long, with long hairs on the dorsal surface; pedicels 1.0-2.5 mm long in flower, 2.5-4.0 mm long in fruit, lanate; sepals four, elliptic to narrowly deltoid, acute, 1-1.5 mm long, lanate abaxially, glabrous adaxially, persistent; petals four, narrowly obovate, 1.5-2.5 mm long, ca. 1 mm wide, glabrous, offwhite; filaments eight, 2.5-4.0 mm long, anthers oblong, ca. 0.4 mm wide, glabrous; ovary lanate, ca. 1.5 mm long, the 2 styles divergent and each 1.5 mm long, basally pubescent but glabrous toward the tips. Capsules 3.0-3.5 mm long (not including style), lanate-villous; seeds oblong, ca. 1.0 mm long, sparsely covered with simple hairs 0.5 mm long. Ecology and distribution. Occurring in patches of short forest on lower summit plateau overlying sandstone, known only from I1l-tepui in the eastern tepui chain of Estado Bolivar, Venezuela, between 2500 and 2630 m elevation. In the size and shape of leaves, inflorescences, flowers, and fruits, Weinmannia ilutepuiensis most closely resembles the Andean W. rollottii Killip, especially variety testudineata (Cuatrecasas) Bernardi. Both species belong to series Dryadifoliae Bernardi (Bernardi, 1963). However, W. ilutepuiensis differs in its dense, lanate-villous indumentum, including the calyx and the capsule (which are glabrous in W. rollottii). On the same helicopter trip to Ili-tepui during which Ronald Liesner collected the type specimen, he also made three other collections of Weinmannia (numbers 23422, 23417, and 23366, all at MO). None of these additional collections fits easily into NovoN 5:125-127. 1995. This content downloaded from 157.55.39.136 on Thu, 19 May 2016 04:37:37 UTC All use subject to http://about.jstor.org/terms