Herbs, annual or perennial, erect, decumbent, or prostrate, terrestrial or epiphytic, glabrous or pubescent, sometimes glandular-dotted. Leaves alternate, opposite, or whorled, glabrous or pubescent, or glandular. Leaf blade conspicuously or inconspicuously veined, lateral veins ascending-arching, or inconspicuous, tertiary veins apparently absent or very faint. Spikes terminal, terminal and axillary, or opposite leaves, densely to loosely flowered. Flowers sessile, borne on surface or in pitlike depressions of rachis, floral bracts glabrous or glandular-dotted; stamens 2, attached at base of ovary; stigma 1, sometimes cleft. Fruits sessile or stipitate, globose, ovoid, oblong, or pyriform, surface warty, minutely reticulate, or faintly striate, ± viscid; beak mammiform or elongate, straight, bent, or hooked.
Mostly tropical and subtropical worldwide, especially tropical America and s Asia.
Species ca. 1000 (7 in the flora).
Many species of Peperomia are used as houseplants, greenhouse plants, and, in warm regions, garden plants.
In addition to the species below, Peperomia simplex Hamilton has been attributed to southern Florida, but no verifying specimens have been seen. A single specimen of Peperomia emarginella (Swartz ex Wikström) C. de Candolle is in the herbarium of the New York Botanical Garden. The specimen may be from southeastern United States.
|1||Stems strigose; leaves opposite or whorled, sometimes proximal leaves alternate.||Peperomia humilis|
|1||Stems glabrous or mostly so; leaves alternate.||> 2|
|2||Plants with numerous black, glandular dots.||Peperomia glabella|
|2||Plants without black, glandular dots, or leaves occasionally with yellowish, resinous or pellucid dots.||> 3|
|3||Leaf blade rounded, truncate, cordate, or auriculate at base.||> 4|
|3||Leaf blade narrowly to broadly cuneate, attenuate, or acuminate at base.||> 5|
|4||Leaf blade auriculate and ± clasping at base; petiole absent or to ca. 3 mm.||Peperomia amplexicaulis|
|4||Leaf blade rounded, truncate, or cordate at base, never clasping; petiole ca. 1/2 length of blade.||Peperomia pellucida|
|5||Beak of fruit mammiform or conic, 0.2 mm or less; leaf blade elliptic, lanceolate, or oblanceolate; petiole slightly dilated and clasping at base, decurrent in lines or conspicuous interrnodal wings along stem.||Peperomia alata|
|5||Beak of fruit elongate, 0.5–1 mm; leaf blade oblanceolate, elliptic-obovate, ovate, or spatulate; petiole not dilated at base, if appearing to be clasping, then not decurrent in lines or wings along stem.||> 6|
|6||Peduncle with microscopic, spiculelike hairs; beak of fruit filiform above conic base, abruptly hooked near apex.||Peperomia obtusifolia|
|6||Peduncle glabrous; beak of fruit tapering smoothly from broadened base to sharply acute apex, straight, bent, or gradually hooked from about middle.||> 7|
|7||Leaves petiolate; leaf blade slightly decurrent along petiole, neither auriculate nor clasping.||Peperomia magnoliifolia|
|7||Leaves sessile or nearly sessile; leaf blade auriculate at base, ± clasping.||Peperomia amplexicaulis|