Peperomia ainana is a species of epiphyte in the genus Peperomia that is endemic in Peru. It grows on wet tropical biomes. Its conservation status is Threatened.
The type specimen were collected near RÃÂo ApurÃÂmac, Peru at an altitude of .
Peperomia ainana is a moderately tall, unbranched, and smooth-textured herb. Its stems are 2 to 4 mm thick. The leaves are arranged alternately and are ovate in shape with a pointed tip. The leaf base is rounded or nearly cut straight across, tapering abruptly at the petiole. Each leaf blade measures in length and in width. The leaves feature multiple nerves, with two to three primary veins on each side of the midrib; the larger of these veins branch once or twice like the central rib. When dried, the leaves are thin and green. The slender petioles range from long. The flower spikes develop from a series of lateral branches, and are long and 2 mm thick. These spikes are borne on a peduncle of equal length. The floral bracts are rounded and peltate, shield-shaped with the stalk attached to the center. The ovary is globose and tipped with a small point, featuring an oblique stigma.
It was described in 1936 by William Trelease in ', from specimens collected by Ellsworth Paine Killip & Dorothea Eliza Smith. It got its name from the location where the type specimen was collected.
It is endemic in Peru. It grows on a epiphyte environment and is a herb. It grows on wet tropical biomes.
This species is assessed as Threatened, in a preliminary report.