Durian - Species

Species

Durian trees are large, growing to 25–50 metres (80–164 ft) in height depending on the species. The leaves are evergreen, elliptic to oblong and 10–18 centimetres (4–7 in) long. The flowers are produced in three to thirty clusters together on large branches and directly on the trunk with each flower having a calyx (sepals) and five (rarely four or six) petals. Durian trees have one or two flowering and fruiting periods per year, although the timing varies depending on the species, cultivars, and localities. A typical durian tree can bear fruit after four or five years. The durian fruit can hang from any branch and matures roughly three months after pollination. The fruit can grow up to 30 centimetres (12 in) long and 15 centimetres (6 in) in diameter, and typically weighs one to three kilograms (2 to 7 lb). Its shape ranges from oblong to round, the colour of its husk green to brown, and its flesh pale-yellow to red, depending on the species. Among the thirty known species of Durio, nine of them have been identified as producing edible fruits: D. zibethinus, D. dulcis, D. grandiflorus, D. graveolens, D. kutejensis, D. lowianus, D. macrantha, D. oxleyanus, and D. testudinarum. There are many species for which the fruit has never been collected or properly examined, however, so other species with edible fruit may exist. The durian is somewhat similar in appearance to the jackfruit, an unrelated species.

The name durian comes from the Malay word duri (thorn) together with the suffix -an (for building a noun in Malay). D. zibethinus is the only species commercially cultivated on a large scale and available outside of its native region. Since this species is open-pollinated, it shows considerable diversity in fruit colour and odour, size of flesh and seed, and tree phenology. In the species name, zibethinus refers to the Indian civet, Viverra zibetha. There is disagreement regarding whether this name, bestowed by Linnaeus, refers to civets being so fond of the durian that the fruit was used as bait to entrap them, or to the durian smelling like the civet.

Durian flowers are large and feathery with copious nectar, and give off a heavy, sour, and buttery odour. These features are typical of flowers pollinated by certain species of bats that eat nectar and pollen. According to research conducted in Malaysia in the 1970s, durians were pollinated almost exclusively by cave fruit bats (Eonycteris spelaea), however, a 1996 study indicated two species, D. grandiflorus and D. oblongus, were pollinated by spiderhunters (Nectariniidae) and another species, D. kutejensis, was pollinated by giant honey bees and birds as well as bats.