E. schomburgkii Bentham (Mesquita, 1990: 168, figs. 34-37). Fig. 18A-G.
Throughout its discontinuously far-flung range E. schomburgkii is remarkably stable in characters of the foliage and consequently in general aspect, and over most of that range equally so in characters of flower and fruit. There are, nevertheless, some anomalous collections that foreshadow, as yet only tentatively, one or more cryptic taxa at least as distinct from typical E. schomburgkii as E. glaziovii has turned out to be (Mesquita, l.c., infra). The pod of typical E. schomburgkii, invariably, so far as known, outside the Amazon basin and prevalently within it, has ligneous valves 3-6 mm thick in section at their thickest point, and immersed sutures (hence a blunt outer margin). Occasionally, in French Guiana (Serv. Forest. 202M, 7695, NY) and again in western Amazonian Brazil (ríos Solimões and Purús, Krukoff 8816, Prance 13652, both NY) the valves are only about 1-2.5 mm thick at their thickest point and the sutures are externally evident, sometimes shallowly sulcate lengthwise. The individual seed-chambers of the thicker pod are not differentiated externally, but in the discoid thinner pod the valves are at least shallowly depressed between seeds, as in the pods of E. cyclocarpum. It is tempting to associate the smaller flower with the woodier pod, and the larger flower of E. oldemanii with the thinner pod, especially since the latter have both been found in the neighborhood of Cayenne; but the connection can be made only by observing one and the same tree at anthesis and in fruit, states that never coincide. As against this hypothesis it must be recorded that small-flowered E. schomburgkii also occurs in typical form in Atlantic French Guiana, and no instance of large flowers has come to light as yet in upper Amazonia.