Momordica subangulata Seeds | Wild Bitter Gourd

Slender climbing vine with lobed leaves, pale yellow flowers and small warty green fruit — Wild bitter gourd (Momordica subangulata): Cucurbitaceae, southern China to Malesia

LATIN NAME: Momordica subangulata

COMMON NAME: Wild Bitter Gourd

Plant Profile

Wild bitter gourd is a slender, soft-stemmed climber of warm forest edges, with tendrils that find a support in hours and stems that run several metres a season. The leaves are lobed and thin, the flowers are pale yellow and dioecious — male and female on separate plants — and the fruit is small, pointed, warty and green, turning orange-red as it ripens. Then it does the thing that makes Momordica worth watching: the fruit splits into three curling valves, flinging its seed out and exposing bright red arils. It grows from southern China through Indochina to India and Malesia, usually on disturbed ground, thickets and the margins of cultivation. The cultivated form in parts of Thailand and Vietnam, sometimes treated as subsp. renigera, is grown as a vegetable and picked young, before the fruit turns.

Science & Biotechnology

The explosive dehiscence of Momordica fruit is a dispersal mechanism with a measurable energetics: the pericarp dries under tension, the sutures weaken, and the valves spring apart, throwing seed a couple of metres. The red aril around each seed is a reward for birds, which eat it and pass the seed intact. The genus is also the source of some of the most studied bitterness compounds in the cucurbits — the cucurbitane triterpenoids, including momordicin and charantin, which are the basis of the fruit’s long use in blood-sugar research. That work has been done mostly on the cultivated bitter melon, M. charantia, and should not be extended wholesale to this wild relative, which has different fruit chemistry and a much smaller edible fraction. The dioecious breeding system means fruit set depends on having both sexes present.

Uses & Benefits

In its native range the young fruit is eaten as a bitter vegetable, stir-fried or stuffed, and the young shoots are cooked as greens; the red aril is sweet and edible, but the seed inside is not. It is also a medicinal plant in local practice, with the root and the whole vine used in decoctions, though the evidence base is local and largely unrecorded in the international literature. For a garden in a warm climate it is a quick, cheerful climber for a fence or a trellis, flowering within two months of sowing and fruiting until the first cold. It is not a plant for a small pot, and it needs a support it can grip. In cool climates it is a greenhouse annual, sown fresh each spring, and it will not survive a frost.

Growing from Seed

Soak the seed for a day, then nick the hard edge with a knife and sow it on its side in a gritty mix at 25 to 30 °C; germination is fast, usually within a week, and the seedling climbs almost immediately. Give it a strong trellis and full sun, and water generously — this is a plant of warm, wet edges, not of dry ground. Feed it lightly once the first flowers appear, and pinch the leading shoot if it outgrows its space. Because the species is dioecious, sow several seeds and keep at least two plants until the sex is clear, then retain a male among the females. Pick the fruit young for eating; leave a few to ripen if seed is wanted for next year.

Our Take

A fast, curious climber whose exploding fruit is worth the trellis space, and whose bitterness is best respected rather than marketed.

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