Kachang-kachang
Aegiceras corniculatum
Family Primulaceae
updated
Jan 2013
Where seen? A rare shrub. According to Ng, it was found
in various northern sites and Pulau Unum. According to Hsuan Keng,
it was found in mangroves including Tuas, Changi, Lim Chu Kang and
Pulau Ubin. According to Davison, it is found on Pulau Unum, Sungei
Khatib Bongsu, Sungei Mandai, Pasir Ris Park, Lim Chu Kang and the
Western Catchment. Elsewhere, it is characteristic of the outer,
seaward fringe of mangroves and usually appears as an isolated shrub,
never forming a conspicuous part of the community. According to
Burkill, it likes light and is never found under the shade of mangroves.
Instead, it is 'abundant' on mud above the high water mark. According
to Giersen, it tolerant of a wide range of salinity, soil and light
conditions and most commonly found in back mangroves that are inundated
by the normal high tide, in sandy substrates. It is found from India
to New Guinea and common in the mangroves of Malaya. According to
Tomlinson, it is widely distributed from Sri Lanka to South China
through the Malay archipelago to Polynesia and northeastern Australia
to New South Wales.
Features: Shrub or low tree
growing to 6m tall, but in Singapore it usually grows up to only
1-2m tall. Bark fissured with numerous lenticels. Roots running
along the soil surface.
Leaves oval (4-8cm) thick, leathery dark green glossy above, paler
below. The leaves are arranged alternately in spirals. No stipules.
The leaves often encrusted with salt crystals.
Flowers (1-2cm) in a dense cluster of 10-20. 5 white or pale pink
petals that fold back when mature, fragrant. They are rich in nectar.
According to Tomlinson, from the structure of the flowers and the
fact that these produce nectar and a fragrance, the plant seems
to be pollinated by insects. But there are no records of flower
visitors.
Fruit long (5-8cm) cylindrical with pointed tip, usually curved.
They resemble long beans, tiny bananas or horns and are light green
ripening to pink or purple. 'Corniculatus' means 'with little horns'
while the Malay name 'Kachang' means 'bean'. Another Malay
name for it is 'Kuku Lang Laut' which means 'Claw of the
Sea Eagle'. Each fruit contains a single elongated seed which undergoes
cyptovivipary, i.e., it germinates while on the parent tree, but
does not emerge through the fruit wall until the propagule falls
off. The fruits and seeds are well adapted to water dispersal.
It is the preferred local food plant for caterpillars of the moths,
Anarsia species, Archips species, Darna trima, Gonodontis clelia;
Phyllocnistis species and Zeuzera conferta.
Human
uses: According to Burkill, the bark is used as a 'fish
poison', i.e., to stun fish and scoop them up. He identifies the
toxin as a saponin. The seeds also contain the same poison. The
leaves were eaten by poor people in the Moluccas raw or cooked,
while women wore the scented flowers in their hair. According to
Giersen, the wood is used to make charcoal. The flowers are probably
an important source of nectar for local honey industries.
Status and threats: This plant
is listed as 'Endangered' in the Red List of threatened plants of
Singapore. It is threatened by habitat loss and oil spills.
|
Kranji Nature Trail, Apr 11
Kranji Nature Trail, May 11
|