This species, represented by several collections from Amazonia, is found only infrequently in Guiana and heretofore has not been reported from Amapa. Over its range E. polyphylla exhibits wide variation in leaflet size and pubescence. Guiana collections examined (Suriname. Marowijne R., N. of Albina, Lanjouw & Lindeman 277; Kwakoegroen, Maguire & Stahel 25008; Pires et al 51355 cited above) generally resemble those of Para and Amazonas in having leaflets of moderate to large size (11 x 3 mm to 20 x 6 mm), with scattered pubescence on the undersurface. Collections from Guayana (Venezuela. Amazonas: Rio Casiquiare, Williams 15760; Rio Orinoco, Yapacana Cano, Wurdack & Adderley 43039) have somewhat smaller leaflets (9x2 mm to 17 x 4 mm), which also bear scattered hairs on the undersurface. Material from the Rio Madeira (Brazil. Amazonas: Mun. Humayta, Tres Casas, Krukoff 6334 and 6480) shows denser pubescence on the leaflets, and that from Ecuador (“Hac. Arcadia,” Heinrichs 508) and Peru (Loreto: Middle Ucayali, Pucallpa, Tessmann 3284; lower Rio Huallaga, Killip & Smith 27546; near Iquitos, Klug 290; Balsapuerto, Klug 2850) is copiously pubescent on the undersurface.
By contrast, E. polystachya DC., occurring throughout Guiana, is relatively constant over its more extensive range, showing only slight and uncorrelated variation in leaflet pubescence. Leaflet number per pinna in this species ranges up to 9 or 10 pairs.