Alsomitra macrocarpa, commonly known as Javan cucumber,[1] is a species of gourd-bearing liana belonging to the pumpkin family Cucurbitaceae.

The plant was first described under the name Zanonia macrocarpa in 1825 by Carl Ludwig Blume from fruiting material collected on Mount Parang in Java.

The fruits or pepos are football-sized (about 300mm diameter) and bell-shaped, suspended high in the forest canopy, and are densely packed with large numbers of seeds.

Remarkably the seeds have large, papery wings and when ripe they fall from the underside of the fruit and glide long distances.

The seed moves through the air like a butterfly in flight — it gains height, stalls, dips and accelerates, once again producing lift, a process termed phugoid oscillation.