Gen info
Genus is named in honor of Robert James Petre, 8th Baron Petre of Ingatestone Hall in Essex, an English patron of botany. Sandpaper name derives from the rough-textured leaves.

Botany
Sandpaper vine is a slender, woody climber. Leaves are leathery, stiff and crisp, opposite, oblong-ovate, up to 6 to 12 centimeters long, the upper surface dull green and the lower surface bright emerald green, and with entire or slightly sinuate margins. Both surfaces are harsh and rough-textured like sandpaper. Flowers are violet, purple, or bluish, and 5-lobed, in long, terminal racemes. Sepals are showy, spreading, and star-shaped. Corolla is spreading, 5-lobed, violet, smaller than the calyx. Fruit is small, 1- to 2-seeded, embedded in the short calyx tube.

Distribution
- Introduced to the Philippines probably after the Second World War.
- Native to tropical America.

Parts used
Leaves.

Uses
Folkloric
- No reported folkloric medicinal use in the Philippines.
- In Bangladesh, used for diabetes.
- In Jamaica, reported use as abortifacient.

Studies
• Antidiabetic: Study evaluated the antihyperglycemic potential of leaves of P. volubilis and stems of E. agalloch. The methanolic extracts of leaves of P. volubilis showed dose-dependent and significant reductions of serum glucose in mice.

Availability
Wild-crafted.