Monographs Details: Orthomene prancei Barneby & Krukoff
Authority: Barneby, Rupert C. & Krukoff, Boris A. 1971. Supplementary notes on American Menispermaceae. VIII. A generic survey of the American Tricilisisae and Anomospermeae. Mem. New York Bot. Gard. 22: 1-89.
Family:Menispermaceae
Description:Latin Diagnosis - O. hirsutae affinis sed ramuHs foUisque inferne pilis brevibus ad 0.5 mm usque longis setulosa (nee longe patule hirsuta), foliorum laminis planis obovatis obtusis obscure apiculatis (nee bullatis ovato-ellipticis acuminatis), venisque secundariis utrinque prominulis (nee facie superiori profunde impressis) diversa. Frutex scandens ramulis annotinis subvolubilibus petiolisque pilis luteis fuscisque rarioribus commixtis dense setulosis, vetustiorbus nigricantibus glabratis parce lenticellatis; petiolus 8-15 mm longus apice parum incrassatus; foliorum lamina subcoriacea utrinque nitida supra (sicca) atrobrunnea inferne paullo pallidor, obovata obtusa minute apiculata 5.5-9 cm longa, 3-5.5 cm lata, supra tantum secus venas primarias infra secus venas omnes densius et intra venas parcius setulosa, e basi late cuneato 3-nervia, nervis lateraUbus ultra mediam laminam adscendentibus, costa nervos secundarios utrinque 2-3 gignenti, his cum tertiariis reticuloque utraque facie sed inferne altius prominulis, reticuli areolis ultimis ± 0.5 mm diam; pedicelli 2 solitarii supra-axillares fructiferi ± 1 cm longi vix 1.5 mm diam; drupae subsymmetrice ellipsoideae paullo compressae 24 mm longae, 12 mm latae, 10 mm crassae, cicatrice stylari minuto exaete apieali praeditae exocarpium coriaceum (siccum) nigrum subnitidum minute rugulosum, 0.5-0.7 mm crassum, mesocarpium mucilagineum tenue statu sicco evaporatum, endocarpium tenuiter lignosum ± 0 .4 mm crassum extus sublaeve sed inciso-reticulatum dorsoque longitrorsus seriatim foveolata; condyli lamina ± 2 mm lata, ala interiori dorsaU nulla.

Distribution and Ecology - BRAZIL. Amazonas: basin of Rio Urubu, G. T. Prance, D. Philcox, W. A. Rodrigues, J. F. Ramos & L. G. Farias 5011 (INPA, NY-holotype).

Discussion:

Type locality: banks of Rio Urubu, between cachoeira Iracema and Manaus-Caracarai road.

This is evidently more closely related to O. hirsuta than to O. schomburgkii, though readily distinguished by its much shorter pubescence (hairs at most 0.5, not up to 1.5 mm long) and obtuse, obovate, essentially plane leaf-blades. The leaf-blades of O. hirsuta are elliptic-ovate-acuminate and bullate by the sharp and deep impression of the secondary venation. The fruits of 0. hirsuta and 0. prancei are scarcely distinguishable; in both the endocarp bears lengthwise along the dorsal side two parallel rows of shallow pits corresponding with low bumps on the interior wall of the seed-cavity; the testa of the endocarp in O. schomburgkii is undecorated.

A field note describes the corolla as green, but there are no flowers in the specimens examined.