Malpighia glabra L.

Shrub or small evergreen tree, 2-3(-6) m tall, with spreading, more or less drooping branches on a short trunk. Leaves opposite, ovate to elliptic-lanceolate, 2-8 cm x 1-4 cm, entire or undulating, dark green and glossy above, petiole short. Inflorescences sessile or short-peduncled axillary cymes with 3-5 flowers; flowers bisexual, 1-2 cm in diameter, pinkish to reddish; calyx with 6-10 large sessile glands; petals 5, fringed, slender-clawed; stamens 10, filaments united below. Fruit a bright-red, juicy drupe, depressed-ovoid, 1-3 cm in diameter and weighing 3-5 g, usually in pairs or threes, obscurely 3-lobed; skin thin, flesh soft, orange, acid to subacid. Seeds 3, triangular, ridged. In Florida, 'Florida Sweet' is a high-yielding cultivar. A distinction is sometimes made in nomenclature between wild and cultivated (improved) plants, the latter being called M. punicifolia L. It is now, however, generally accepted that both taxa belong to M. glabra. M. coccigera L. and M. urens L. are incidentally cultivated in South-East Asia for the same purposes as M. glabra.

In Puerto Rico flowering appeared to be independent of the daylength and several cropping periods are possible per year, especially with alternating dry and rainy periods. The flowers are pollinated by insects; honey bees substantially improve fruit set. Self- and cross-incompatibiliy have been reported. Fruits ripen completely 3-4 weeks after flowering. In Puerto Rico the large-fruited (up to 20 g/fruit) selection B-15 is most important.

The soil should preferably be rich, deep and well drained, with a pH above 5.5. On calcerous soils the plants require additional micronutrients, on acid soils addition of lime is required.

Acerola can be grown almost anywhere in the tropics and warm subtropics. Young plants are killed by frost, but mature trees survive brief exposure to -2 deg. C. The plants tolerate long periods of drought and do not stand waterlogging.

Fully developed seeds should be used for planting. The germination of the seed is slow (5-50%). Acerola may also be propagated vegetatively by cuttings, budding or grafting.

The recommended spacing is 3-4 m on the square, or in double rows, e.g. (4 + 2) m x 3 m. NPK fertilization twice a year and application of organic material are recommended for Puerto Rico. Bearing will be enhanced if mature plants are judiciously pruned after the main crop, followed by a top dressing.

Diseases: Acerola is very susceptible to the root-knot nematode Meloidogyne incognita var. acrita. It can be controlled by soil fumigation, mulching and regular irrigation.

Ornamental: The plants have ornamental value. Boundary or barrier or support: The plants are suitable for hedges. Other services: The plants are very suitable for backyards and places where children play (to eat the fruits and to climb the trees).

Food: The sour fruits are eaten fresh, but more often preserved with sugar, e.g. in the form of jam. Juice is used commercially to enrich other fruit juices low in vitamin C. Tannin or dyestuff: The bark has been used for tannin. Timber: The wood, which is hard and heavy, can be used for small utensils. Medicine: The fruits are considered beneficial against liver problems, diarrhoea, dysentery, coughs and colds.