Description: A medium-sized tree usually with a straight trunk, but often branched low. Leaves are alternate, compound, and the leaflets are placed alternately relative to each other. The leaflet number is usually even, but the final leaflet is angled slightly to one side, appearing terminal. At the base of the final leaflet is a short stalk, angled away from the leaflet. All leaf parts and small branchlets are covered with dense, red hairs.

Reproduction: Flowers are produced in terminal clusters during the dry season.

Distribution: Found on the Pacific half of the isthmus, from BCI south, where it can be quite common along around roads, and very common around Gamboa in open areas or at the forest edge. Not common inside the forest, although widespread.

Similar Species: See LK cupasy Cupania sylvatica LK2 for a discussion of the genus Cupania and the similar Matayba. Like its relatives, C. rufescens has compound leaves with alternating leaflets, and a final leaflet that is angled slightly, along with a point at the base of the final leaflet. But the dense red hairs set this species apart in central Panama.

Descripción: Árbol de 10 a 25 m de alto. Tronco ligeramente acanalado. Corteza exterior negra o gris. Ramitas terminales acanaladas y con pelos hirsutos y ferruginosos. Hojas imparipinnadas y alternas, con 3-9 folíolos, alternos en el raquis. Folíolos de 8-25 x 3-10 cm, oblongos a obovados, con ápice redondeado a obtuso, bordes dentados o enteros y base aguda. Los folíolos son coriáceos y tienen pelos hirsutos en el envés. Las plantas juveniles pueden presentar hojas simples y de mayor tamaño en comparación con los adultos. Pecíolo de 2-6 cm de largo y pulvinado en la base. Raquis con crecimiento indefinido y terminado en una pequeña prolongación aguda después del último folíolo. La especie es polígama. Flores blancas. Frutos en cápsulas triloculares y aplanadas, de 1.5-2 cm de largo, tornándose rojos y dehiscentes al madurar. Semillas negras y rodeadas en la base por un arilo amarillo.

Datos Ecológicos: La especie crece a bajas elevaciones, en bosques húmedos. En Panamá se encuentra en las provincias de Bocas del Toro, Chiriquí, Darién, Los Santos, Panamá y Veraguas. Florece y fructifica de marzo a junio. Las flores son visitadas por abejas y otros insectos. Las semillas son dispersadas por la abertura de los frutos y los animales.

Especies Parecidas: A menudo se confunde con LK cupagu Cupania guatemalensis LK2 , pero en C. guatemalensis los folíolos son más pequeños y los frutos son cápsulas globosas.

Usos: La madera es empleada para postes de cercas, leña y horcón para la construcción de viviendas rurales.

Tree, to 15 m tall; trunk to 25 cm dbh, sulcate at least when young; outer bark with shallow, horizontal and vertical fissures, flaking off to expose reddish inner bark; wood cream-colored, with sweet odor; younger stems densely ferruginous-hirsute, obscurely 5-ribbed. Leaves pinnate; rachis conspicuously hirsute; leaflets 3-7 (9), obovate-oblong, mostly rounded at apex (sometimes obtuse or acute), often inequilateral at base, the larger 7-22 (33) cm long, 3.5-10 cm wide, glabrous above but with densely pubescent midrib, conspicuously hirsute below especially on veins, the margins entire to usually denticulate (serrate on juvenile plants); all veins prominent, the major laterals impressed above; simple leaves on juvenile plants to 45 cm long and 15 cm wide. Panicles stout, densely floriferous, upper-axillary, +/- equaling leaves, densely hirsute; flowers white, 5-parted; calyx densely pubescent, 2.8-3.3 mm long, equaling corolla, regular; petals obovate, pubescent, the scales fused along the margin at base; disk orange, prominent, nearly glabrous; stamens 8, the filaments villous on basal three-fourths; staminate flowers opening before bisexual flowers and mostly deciduous when bisexual flowers open, with the stamens to 3.5 mm long, exserted; anthers ca 1 mm long, attached to filament at middle, the thecae divergent in lower half; ovary and style very densely pubescent, the trichomes stiff, straight, usually exceeding stigmas; ovary narrowly ovoid, strongly 3-angulate; style and stigmas less than 2 mm long; stigmas 3, +/- erect; bisexual flowers with the stamens 2-2.5 mm long, not exserted; anthers smaller than in staminate flowers, otherwise similar; ovary ovoid, ca 2 mm high, the pubescence as in staminate flowers but with style and stigmas not exceeded by trichomes; style +/- equaling ovary; stigmas 3, recurved. Capsules in dense clusters, burnt-orange to Indian red, sharply 3-sided, 1.5-2 cm broad, nearly as long as broad, densely pubescent outside, less so inside, dehiscing broadly along the angles, each angle narrowly winged; seeds 3, obovoid, ca 1 cm long, black, shiny, partly enveloped by a yellow to greenish aril. Croat 14627. Frequent in the forest, especially the young forest. Seedlings are often abundant; they are more deeply toothed and more densely hirsute and often look quite unlike adult plants. Flowers in the early to middle dry season, usually in February and March. The fruits mature in late dry and early rainy seasons, from late April to June. Dehisced fruit valves hang on the tree all year. Seeds are probably bird dispersed. Mexico to Colombia, Venezuela, the Guianas, and Brazil. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Los Santos, Panama, and Darien, from tropical wet forest in Darien, and from premontane rain forest in Chiriqui and Veraguas. See Fig. 339.