Description: Small tree, seldom more than a 5-7 m tall, with a crown reaching close to the ground. Leaves are opposite, tightly clustered at the end of branches, dark, shiny green on the top, densely pubescent on the underside.

Reproduction: Flowers and especially fruits are well-known. The flowers are bright yellow, produced in clusters above the leaves; the petals are narrow near the base, then broaden. Fruits are 2-cm berries, green initially, maturing yellow, produced for much of the year.

Distribution: Abundant in farmland, residential areas, throughout the drier Pacific slope; common along road from Panama City to Gamboa and in Gamboa. Very few along the first part of Pipeline Rd., and absent in any dense, mature forest. Resistant to fire, and common in burned grasslands of rural Panama.

Similar Species: Most easily known by its occurrence around human settlements, where the dense, opposite leaves with a densely hairy underside distinguish it. There is no need to know it in the forest. Flowers are conspicuous and distinctive, and the fruit known by most every Panamanian.

Uses: The fruit is very popular in Panama, usually made into a drink. Fruits are often sold along the Panamerican Highway stuffed in glass bottles.

Descripción: Árbol de 5 a 15 m de alto. Tronco con la corteza exterior gris o negra, a veces con manchas blancas o anaranjadas. Corteza interior roja, fibrosa y amarga. Ramitas terminales simpodiales y cubiertas de pelos. Hojas simples y opuestas, de 5-15 x 3-9 cm, ovadas o elípticas, con ápice agudo o acuminado, bordes enteros y base aguda. Las hojas son verdes en el haz y grises por el envés, debido a la presencia de pelos en forma de ‘T’, visibles con una lupa. Estípulas axilares. Pecíolo de 0.8-1.5 cm de largo. Flores amarillas, tornándose rojas o anaranjadas al madurar. Sépalos con un par de glándulas en la superficie exterior. Frutos en drupas globosas, de 0.7-1.5 cm de largo, verdes, tornándose amarillos o anaranjados al madurar.

Datos Ecológicos: La especie crece a bajas y medianas elevaciones, en bosques secos o húmedos de todo el país. Común y fácil de observar a orillas de carreteras, pastizales y sabanas de la vertiente del Pacífico en Panamá. Los árboles de nance dejan caer parcialmente sus hojas durante la estación seca, pero las reponen a inicios de la estación lluviosa. Antes de caer las hojas se tornan de color rojo en la copa del árbol. Florece y fructifica de marzo a octubre.

Especies Parecidas: A menudo se confunde con LK byrssp Byrsonima spicata LK2 , pero B. spicata es un árbol de mayor tamaño que tiene hojas más pequeñas y crece en bosques húmedos o muy húmedos. LK byrsc1 Byrsonima crispa LK2 tiene hojas, flores y frutos muy parecidos, pero en B. crispa las hojas no presentan el envés gris.

Usos: La madera es empleada en la fabricación de muebles, gabinetes, pisos, puertas, marcos, ventanas, leña y carbón. La corteza se utiliza para curtir y teñir pieles. También tiene uso medicinal, por sus propiedades astringentes se emplea en cocimiento para curar la diarrea, las inflamaciones de la vejiga, la sarna y en la cicatrización de heridas. Los frutos maduros son comestibles y con ellos se preparan refrescos, jaleas, dulces, helados y conservas.

Nance, Nance blanco, Nance Colorado Tree., 4-13 m tall, to 30 cm dbh; bark fissured and lenticellate; wood dull reddish-brown, hard, heavy; younger parts densely downy-tomentose (sparsely on upper leaf surface and becoming glabrate); stems bearing prominent leaf scars. Petioles ca 1 cm long, stout; blades obovate to elliptic or ovate, acuminate, narrowed to an acute or obtuse base, 7-14 cm long, 3-8 cm wide, densely pubescent below becoming glabrate except on midrib in age; midrib +/- arched. Pseudoracemes terminal, usually solitary, to 20 cm long; pedicels to 1.5 cm long; flowers many, yellow, becoming red-orange in age; sepals each bearing 2 conspicuous glands, blunt, recurved, glabrous inside; petals clawed, 10-13 mm long, the blade orbicular, often concave, +/- equaling length of claw, the margin irregular, 1 petal often smaller and held somewhat erect, the others spreading to reflexed; stamens 10, 4-5 mm long, interspersed with long straight trichomes; anthers introrse equaling length of styles, the thecae prominently raised, shedding pollen in bud, the connective thickened; ovary usually pubescent; styles 3, distinct, slender, longer than stamens, persisting on young fruits. Drupes +/- globose, 1-1.5 cm diam, green turning yellow to reddish; pyrenes 1-3. Croat 6068, 8702. Locally common along the shore; infrequent in the forest, usually near old settlement sites. Flowers from November to July, principally from March to June. Each tree flowers for about 6 weeks. The fruits mature principally in August and September. Leaves turn old and reddish, falling in the dry season and gradually growing out again in March just before the greatest flush of flowering. Allen (1956) reported that the species had fruits during April and May in Costa Rica, but the fruits were probably not ripe. Byrsonima crassifolia may be confused with B. cumingiana Adr. Juss., which ranges from Nicaragua to Colombia. B. cumingiana is distinguished by having a glabrous ovary and leaves that are more thickly coriaceous and rugose above. Veracruz, Mexico, south to Brazil and Paraguay; West Indies. In Panama, widespread and ecologically variable; known from tropical moist forest in the Canal Zone, Bocas del Toro, Veraguas, Herrera, Coclé, Panama, and Darién, from premontane dry forest in Coclé, from tropical dry forest in Los Santos and Panama, from premontane moist forest in the Canal Zone, from premontane wet forest in Chiriqui, and from tropical wet forest in Colon. Tosi (1971) listed this species as characteristic of tropical dry and tropical moist forests in Panama.

Bocas Species Database

Natural History Notes: Wood is used in the making of furniture, floors, doors, frames, firewood and coal. The bark is used to dye skins. Also when cooked it is used to heal diarrhea, bladder infections, mange and help heal scars. The fruits are edible and used to make juice, jams, ice crem and other sweets.   Characteristics: Tree that reaches from 5 to 15 m in height. It has simple and opposed leaves, with underside gray colored. Flowers are yellow and turn orange when older. Fruits are small and round, turning yellow or orange when ripe.