1526

2: Edible fruits and nuts

Muntingia calabura L.

Sp. Pl. 1: 509 (1753).

ELAEOCARPACEAE

2n = 28

Capulin, Jamaica cherry (En). Indonesia: cerri, kersen, talok (Java). Malaysia: kerukup siam. Philippines: datiles. Cambodia: krâkhôb barang. Laos: khoom sômz, takhôb. Thailand: takhop farang. Vietnam: trúng cá, mât sâm.

Capulin is a neotropical species that — although not cultivated — has become pantropical. It was introduced in the Philippines late in the 19th Century, but its incredible capacity for establishment 'under foot' quickly has made it one of the most common roadside trees in South-East Asia.

School children compete with bats and birds for the sweet berries, which can also be preserved, as indicated by the Sri Lankan name 'jam fruit'. Old sources in the Philippines mention the use of flowers to prepare an infusion against headaches, colds, etc. The pliable bark can be used as rough cordage. The tree serves as a roadside shade tree; the wood is soft and is valued mostly as fuel.

Per 100 g edible portion the berries contain approximately: water 76.3 g, protein 2.1 g, fat 2.3 g, carbohydrates 17.9 g, fibre 6.0 g, ash 1.4 g, calcium 125 mg, phosphorus 94 mg, vitamin A 0.015 mg, vitamin C 90 mg. The energy value is 380 kJ/100 g.

Small evergreen tree, 3—12 m tall, growing and flowering continuously on fan-like branches; mainline branches becoming erect after leaf fall and so in turn contributing to the formation of the trunk (Troll's architectural model). Branches horizontal, pendent towards the tip, soft-hairy. Leaves simple, ovate-lanceolate, 4—14 cm x 1—4 cm, with prominent asymmetry of the leaf blade base; leaf margin serrate, lower leaf surface greyish pubescent. Flowers in 1—3(—5)-flowered supra-axillary fascicles, hermaphrodite, pentamerous with white petals; number of stamens increasing from 10—25 in the first emerging flower in the fascicle to more than 100 in the last; development of the superior ovary declining in the same order, so that from the third and later, flowers do not normally set fruit. Fruit a dull-red berry, 15 mm in diameter, with several thousand tiny seeds in the soft pulp.

Inflorescences are initiated by the growing shoot along with the subtending leaf, and develop along with this leaf, the fruit maturing shortly before the leaf falls. The flower fascicle is inserted supra-axillary, up to halfway along the internode. In the axil proper of the same leaves, side shoots are formed; these emerge before the inflorescence flowers, but extension growth is delayed until after the abscission of the subtending leaf. Under favourable conditions flowering fascicles are formed with every third leaf, but this may be delayed until the 5th, 7th or 9th leaf or indefinitely. Side shoots are spaced further apart, but like the fascicles, they normally alternate along the branch.
Thus growth and development are neatly structured at the shoot level, in a system which allows continuous extension growth and fruit production. Flexibility is afforded by varying the spacing of the fascicles, the number of flowers per fascicle and the sex expression of each flower. The flowers open just before dawn and last for only a day; bees are the main pollinators. The species is self-compatible and intensive pollination is needed to reach the normal number of several thousand seeds per fruit. The flowers in a fascicle open sequentially at intervals ranging from 4—9 days. Within 2 weeks from the opening of the last flower, the first flower of the following fascicle may already reach bloom. A series of remarkable pedicel movements lifts each flower bud above the plane of the plagiotropic shoot just before anthesis and turns the flower to a pendent position within 2 days from fruit set. Thus the flowers are conspicuous to pollinators and segregated from the concealed fruit. This favours bats as the main dispersers of the seed and reduces the likelihood of the bats damaging the flowers. The fruit ripens in 6—8 weeks from anthesis and the life span of the mature leaf is only slightly longer.
Fresh seed germination is enhanced by passage through the digestive tract of bats. The seed is well-represented in the seed banks of forest soils and requires the high temperature and light conditions of large gaps in the forest for germination; the seedlings do not tolerate shade.

Capulin is a typical pioneer species, colonizing disturbed sites in tropical lowlands which can sustain continuous growth. It thrives at elevations up to 1000 m. In South-East Asia it is one of the most common roadside trees, especially in the drier parts such as in eastern Java. It establishes itself in trodden yards and along shop fronts where no other tree takes root. The preferred pH is 5.5—6.5; salt tolerance is poor.

The tree is not normally cultivated, it spreads spontaneously. Seedlings flower within two years. Air layers made for home gardens fruit straight away. Rich moist soils ensure continuous production which is sustained by replacement pruning. No serious diseases or pests have been reported, apart from bats.

Yellow- and white-fruited types are known and there may be scope for selection.

Capulin is very common but hardly studied in South-East Asia, although the battered appearance of the roadside trees testifies to frequent contacts with students. The species is likely to become more prominent in built-up areas and could play a larger role in gardens.

Bawa, K.S. & Webb, C.J., 1983. Floral variation and sexual differentiation in Muntingia calabura (Elaeocarpaceae), a species with hermaphrodite flowers. Evolution 37: 1271—1282.
Fleming, T.H., Williams, C.F., Bonaccorso, F.J. & Hurst, L.H., 1985. Phenology, seed dispersal and colonization in Muntingia calabura, a neotropical pioneer tree. American Journal of Botany 72: 383—391.
Webb, C.J., 1984. Flower and fruit movements in Muntingia calabura: a possible mechanism for avoidance of pollinator-dispenser interference. Biotropica 16: 37—42.

E.W.M. Verheij

Verheij, E.W.M., 1991. Muntingia calabura L.. In: Verheij, E.W.M. and Coronel, R.E. (Editors): Plant Resources of South-East Asia No 2: Edible fruits and nuts. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea