Species Overview

Native to: Africa, Tropical Asia, Australasia, Pacific

First identified as escaping cultivation in Florida in 1993 (Maguire & Hammer letter) and was initially seen mostly in disturbed areas. Plant communities where balsam pear has now been observed include: scrub, maritime and mesic hammocks, pinelands, beach dune, coastal strand, shell midden, wet flatwoods, floodplain swamp and edges of freshwater swamps. This pioneer species gets shaded out in intact mature hammocks. The fruits and leaves are used medicinally but the seeds are toxic. Sometimes called “stink vine,” the unpleasant smell from handling the plant washes off with water.

Species Characteristics

Family: Cucurbitaceae

Habit: monoecious climbing or sprawling herb, 2-3 m tall. It may be either hairless or slightly hairy. There is a central taproot, from the apex of which the stems spread to climb over any available support.

Leaves: carried singly along the stems on 3-5 cm long stalks, and each leaf is 4-10 cm long, rounded in outline, and deeply 5-9 lobed. The foliage has an unpleasant smell when crushed.

Flowers: occur singly in the upper leaf axils on 2-10 cm long stalks with a small leaf-like bract towards the base. Male flowers have a slender basal swelling which is continuous with the base of the sepal tube, which ends in five blunt sepals. There are five oval yellow petals 10-20 cm long, and five central stamens. Female flowers are similar to the male flowers but have a distinct warty swelling well below the base of the sepal tube and three stigmas. Male flowers appear first and usually exceed the number of female flowers by about 20:1. The flower opens at sunrise and remains open for only one day.

Fruit/Seeds: pendulous cylindrical fruits are egg-shaped and 2-10 cm long (up to 20 cm in cultivated varieties), and covered with longitudinal ridges and warts. At maturity, they turn orange to yellow, and the tips split into three and turn back to reveal the yellow pulp and the bright red arils that enclose the seeds which adhere to the inside of the fruit. Each of the flattened woody seeds is 5-9 mm long, and has finely pitted surfaces.

Distribution in Florida: documented throughout central and south Florida and in 3 counties in the panhandle.

Impacts

Spreads by seed (dispersed by birds and animals) and vegetatively by underground stems. A bane to land managers in restoration areas, it spreads through tree gaps after prescribed burns and invasive plant removal. The vines compete with native vegetation as groundcover and can form dense thickets. It has been described as covering shrubs, and comingling with rare air plants in tall trees in South Florida. It is also problematic in agriculture across the tropics, interfering with the growth of a wide range of vegetables, annual, perennial, orchard and plantation crops by climbing over them, competing for light and possibly for nutrients and water, raising the humidity around their bases, and interfering with access, management and harvesting.

Do not plant.

May be uprooted by hand or hoed out as long as the tap root is cut through at, or just below, ground level.

More research needed.

None known.

Reach out to your local UF IFAS Extension for further assistance with management recommendations.