Description: A very large forest tree with a bizarrely fenestrated trunk. In big individuals, the fenestrations penetrate almost to the center of the trunk, but this is only evident on fallen individuals. The bark is dark brown. Leaves are alternate, compound, with small, rounded leaflets, as many as 20 or more per leaf (sometimes less). The leaflets are not quite opposite one another, and have a notch at the tip. The petiole is swollen and cylindrical at the base.

Reproduction: Large trees are usually fully or partly deciduous toward the end of the dry season. Flowers are fairly large, yellow, with the typical keeled legume form, produced at the end of branches after leaves regrow, from April to June. The fruit is a large wing, with a seed at one end of the wing; it starts green but turns brownish, and is dispersed by the wind from June through the wet season.

Distribution: Uncommon but widespread through Barro Colorado's old forest, and at Soberania. Saplings are scarce and mostly only grow in clearings; usually only giant trees are encountered. We have not found it elsewhere.

Similar Species: As a large tree, the bizarre trunk is frequently taken for a strangler fig; note that sometimes after a host tree dies, a strangler stands on its own. But most stranglers have a host tree underneath, and regardless, stranglers have light colored trunks that are rounded and don't really resemble Platypodium's. Even in a tall canopy, the small leaflets of Platypodium are easy to see; they resemble leaflets of LK schipa Schizolobium parahybum LK2, LK dalbre Dalbergia retusa, LK2 or especially LK myrofr Myrospermum frutescens; LK2 all, however, have cylindrical trunks.

Uses: The wood is hard and heavy, and is used for furniture, tools, or decoration. A section of the trunk with its deep lobes makes an unusual table.

Carcuera, Costilla, Tigre, Canalua Tree, to 30 m or more, usually 75-100 cm dbh; trunk with conspicuous, deep, irregular, longitudinal invaginations in age; bark soft, minutely fissured, the sap becoming reddish-brown in time, with a foul odor at least in younger parts. Leaves alternate, imparipinnate, to 25 cm long; petiole, rachis, petiolule, and underside of blade puberulent; leaflets 10-20, oblong, rounded to emarginate at apex, obtuse to rounded at base, 2.5-7.5 cm long, l-3 cm wide, glabrous above. Inflorescences lax racemes from upper axils; pedicels 8-12 mm long, bracteate near apex; bracts oblong, ca 2 mm long, persistent; calyx ca 4 mm long, turbinate, sparsely appressed-pubescent, the carinal tooth acute, equaling lateral teeth, the vexillar teeth +/- united; corolla yellow-orange; petals clawed; standard reniform, ca 1.8 cm long; keel petals fused only near apex; stamens ca 1 cm long, 2 stamens free, the others in clusters of 4 each; stigma about as long as anthers. Samaras obliquely oblong, to 13 cm long and 3 cm wide, on stipes ca 2 cm long; seminiferous area distal. Croat 5411. Common. Flowers synchronously every two years from April to June (sometimes as early as March), apparently initiated by the beginning of the rainy season. The fruits may be full size by June but mature over a long period, ripening by December or January. Leaves are replaced in the dry season before the time of flowering. A few individuals are out of phase (R. Foster, pers. comm.).

Descripción: Árbol de 20 a 40 m de alto. Copa irregular y dispersa. Tronco acanalado con surcos verticales profundos e irregulares. Hojas imparipinnadas y alternas, con 10-20 folíolos, alternos en el raquis. Folíolos de 2-7 x 1-3 cm, oblongos, con ápice redondeado o emarginado, bordes enteros y base obtusa o redondeada. Estípulas deciduas. Pecíolo de 2-5 cm de largo y pulvinado en la base. Raquis acanalado en la parte superior, a veces terminado en una punta aguda. Flores amarillas. Frutos en legumbres samaroides, de 10-13 cm de largo, verdes, tornándose marrón amarillentos al madurar.

Datos Ecológicos: La especie crece a bajas elevaciones, en bosques húmedos o muy húmedos. En Panamá se encuentra en las provincias de Chiriquí, Colón, Darién, Panamá y Veraguas. Común en la isla de Barro Colorado y los bosques de la parte central del Canal de Panamá. Deja caer sus hojas durante la estación seca, pero las repone a inicios de la estación lluviosa. Florece y fructifica de abril a enero. En el suelo del bosque algunas especies de coleópteros perforan la cubierta de los frutos para depositar sus huevos.

Especies Parecidas: A menudo se confunde con LK myrofr Myrospermum frutescens LK2 , pero en M. frutescens los folíolos presentan líneas translúcidas, lo cual no ocurre en P. elegans.

Usos: La madera es dura y muy pesada, empleada en la fabricación de mangos para herramientas, carpintería, horcones, pilastras y decoraciones internas.