Shrub or treelet to 3 m tall, stem minutely hirtellous, usually somewhat tuberculate. Petiole tuberculate, 0.1-0.7 cm long, minutely puberulent, glabrescent, vaginate to base of blade and extending shortly; blade broadly ovate-elliptic, 4-12 x 2-6 cm, apex obtuse, rounded or slightly acute, base unequally attached to petiole difference 0.2-0.7 cm, shorter side acute to obtuse, longer side rounded or cordate, glabrous or glabrescent above, minutely pubescent on veins below; pinnately veined, secondary veins 4-10, originating from throughout primary vein, anastomosing near margin. Inflorescence erect, 4-14 cm long; peduncle 0.5-2 cm long; spike 2-11 cm long; floral bracts 0.5-0.7 mm in diam., marginally fringed, conspicuously arranged in whorls. Fruits laterally compressed, rounded, glabrous, stigmas 3-4, sessile.
C America present, Guianas present, S Guyana present, S Mexico present, Suriname present, northern S America present
S Mexico, C America and northern S America; in the Guianas reported only from S Guyana and Suriname; 10 collections studied (GU: 6; SU: 3).
Piper tuberculatum and P. arboreum share the same striking character of a very unequal leaf base. Difference at the petiole up to 3 cm. They can, however, be distinguished by the shape and presence of indument on the leaves. In P. arboreum internodes and petioles are smooth or with a few tubercles only; blades are ovate to elliptic, the apex acute to (long-)acuminate, whereas in P. tuberculatum petioles are usually tuberculate, blades relatively smaller and more narrowly ovate-elliptic and the leaf apex obtuse, rounded or only slightly acute. Like several authors (Steyermark 1984: 583; Trelease & Yuncker 1950: 364, f. 330; Burger 1971: 185, f. 8 and Steyermark & Callejas 2003: 726) I consider P. tuberculatum to be a separate species. This in contrast to Tebbs, who found too few differences to keep P. tuberculatum and P. arboreum apart; as they occur in different habitats, Tebbs accepted the two species as subspecies. Piper tuberculatum occurs in dry habitats in contrast to P. arboreum which prefers more moist habitats, swamp or mixed forest and secondary vegetation.