Averrhoa carambola L.

Tree to 25 m tall, 25 cm diam., abundantly branched; branches sometimes drooping; pubescence of short curved whitish to reddish ascending deciduous hairs. Leaves disposed along the branches, 3-8 jugate, the leaflets alternate or subopposite, discolorous, variable in shape, asymmetric, the upper leaflets ellip-tical or ovate, oblong, cuspidate, basally rounded or truncate, the lower leaflets smaller, 1.5-3 cm long, 1-2 cm wide, acuminate or cuspidate, the secondary nerves 4-10 pairs, the pubescence short and even beneath, the nerves pubescent above, the margin appressed ciliate; rachis to 20 cm long, rigid, pubescent; petio-lules thick, 1.5-3 mm long; petioles to 3.5 cm long, pubescent, thickened towards the base. Inflorescences axillary or cauliflorous, of pubescent and glandular cymes united into racemes and these into fascicles or pseudo-panicles; peduncle to 1 cm long; pedicels 3-4 mm long. Flowers with the sepals oblong or obovate oblong, 2.5-3.5 mm long, 1-2 mm wide, obtuse and somewhat emarginate, rarely subacute, a few hairs appressed on the central zone, the margin irregular, hyaline, finely ciliate; petals violaceous, white bordered, linear spatulate, 6.5-9 mm long, 1.5-3 mm wide, clawed, connate at the middle, seldom free, densely glandular inside; stamens enlarged toward the base, connate up to l/5, the anthers orbicular, the connective conspicuous, the longer stamens 2-2.5 mm long, fertile, the short-er stamens without anthers, seldom with rudimentary anthers (D'Arcy & D'Arcy 6799 and others), or rarely with 2 rudimentary thecas separated by a short con-nective, in macrostylous flowers the longer stamens with small glands on the upper half, in mesostylous flowers (most frequent) the short stamens very short, microstylous flowers not seen; pistils 3-4 mm long, sometimes glandular, the ovary ellipsoid, the pubescence scant, appressed, sometimes only on the back of the carpels, the carpels 3-5-ovuled, the styles short, thick, pilose, the stigma enlarged, 2-lobed. Berry greenish or yellow, ovoid or ellipsoid, asymmetric, 8-12.5 cm long, 5-6 cm wide, the carpels uneven, angular, the base and apex 5-lobed, in transverse section 5-rayed; seeds without outer integument.

A tropical plant. Five corners need a warm tropical climate so they are mostly seen in the coastal lowlands below about 50
 altitude. They will grow up to 120
 in the equatorial tropics. Mature trees can tolerate slight frost. Five corner can grow on several different types of soil. The soil should be well drained. It will grow on alkaline soils but is better in acid soils. Plants cannot stand water-logging. It is suited to moist places but performs better in areas where there is some dry season rather than in places with heavy, constant rain. Trees are fairly wind resistant providing the winds are not cold. Trees are stressed by temperatures near 0°C as well as above 37°C. It grows in Nepal to about 300 m altitude. In XTBG Yunnan. It suits hardiness zones 10-12.

Uses. The fruit is eaten fresh or pickled. Leaves and fruits are said to be good against fevers, aphtha, angina, chickenpox, ringworm, headaches, scurvy, dysentery, piles and affections of skin and eyes; they excite the appetite, but may cause vomiting. It is antiphlogistic and a sialogogue. The fruit removes stains from laundry, hands and weapons. See NINGRAT (1893), KOORDERS & VA-LETON (1903), HEYNE (1927), OCHSE (1931), BURKILL (1935), and QUISUMBING (1951).

Trees are grown from seed. Seeds grow easily but in fact only a small number of seeds are fertile. Well developed seeds should be chosen. Seeds are planted in a seed bed and planted out when 15-20 cm high. Because seeds are produced by cross pollination, variation is common. It is therefore better to use budding or grafting. Taking buds off good trees, or grafting twigs from them, onto 1 year old seedling roots, is the commonest method. Marcottage or air layering can also be used, although it is difficult. A spacing of 6 m x 6 m is suitable. Trees need to be grafted if sweeter kinds of fruit are to be selected. Because the seeds are covered by a fatty layer, washing them with soap improves the germination.