NEW INVADER IN NORTH AND NORTH EAST
OF SRI LANKA
( December 10, 2013, Queensland , Sri Lanka Guardian) My recent visit to Sri Lanka in November allowed me to travel around the North (Jaffna, Nagadeepa, Point Pedro) and North East (Trincomalee, Mutur, Passikudha, Batticolo) parts of the country. The invader I noticed was not given attention in Sri Lanka as it has not well noticed by the public and scientists in the country during the last 30 years. Bellyache bush (Jatrophagossypiifolia) is being colonized in some areas of Jaffna peninsula, nagadeepa, trincomalee, Mutur, batticolo and passikudah.
Bellyache bush is considered as one of the worst weeds in tropical parts of the worlddue to its invasiveness, potential for spread and economic, environmental and social impacts.This plant originated from Mexico to southern Brazil. It has been introduced as an ornamental plant in many tropical countries across Australia, Africa, Asia and America. It was recorded in Sri Lanka in 1887 as per herbarium records at Peradeniya Botanical Gardens.
Picture 1: Bellyache bush plant
Bellyache bush is often confused with castor oil plant as both plants are found in the same areas. This plant is an upright, multi stemmed perennial shrub with a shallow root system. Individual plants have a life span of more than 10 years and can grow up to 4 meters, although most plants average between 2-3 meters high.
Picture 2: Fruits and flowers
The branches, stems, leaf stalks and leaf margins covered with tiny, sticky brown hairs. Stem is not woody which exude a sticky sap when damaged.Bellyache bush leaves are alternate and have three to five lobes with very finely toothed margins. The leaf colour initially purplish but green when mature. The length of a leaf is 5.5 14 cm and with is 7.5 to 12.5 cm, rounded in outline. Leaf stalks are 4.5 – 11.5 cm long.
The flowers are small, red or purple on the outside of the petals with a yellow centre. Flowers often found in clusters around the top part of the plant.
The fruit is a 3 lobed capsule, oblong, 1- 1.2 cm long, smooth and bright green when immature. They change to pale green or tan and woody at maturity. A fruit contains 3-4 fresh brown seeds. Each seed is about 8 mm long. Bellyache plants are prolific seed producers with one adult plant producing up to 12,000 seeds a year depending on environmental conditions, density and biotype of the infestation. Plants can produce flowers and fruits after 55 days of initial germination.
Seed capsules (fruits) open explosively on ripening, catapulting seeds up to 13 meters from the adult plant. Research found that the seed viability of this species is about 4 years but some may last 10 years or more under dry conditions.
Bellyache bush seed is spread via water, ants, livestock and other animals (pigs, buffalo) and machinery contaminated with seed. It can also be spread inadvertently if any fill, gravel or bailed straw contains seeds.
Bellyache bush will also regenerate vegetatively from stem and root segments, including dumped cuttings, slashed plants and plants damaged in events such as flooding.
Problems with Bellyache bush
• The fruits of the plant are poisonous to humans and animals. The toxic substance is a toxalbumin which, when eaten, leads to symptoms of gastro-enteritis and eventual death of some animals. There have been many cattle deaths reported in Australia due to bellyache bush poisoning mainly in times of severe drought.
• Bellyache bush seedlings are particularly hardy and competitive. It has been observed to reduce the recruitment of native species in both disturbed and undisturbed areas.
• Bellyache bush can spread into pasture lands forming dense thickets which render land unsuitable for grazing, hinder mustering and obscure fence lines.
• Bellyache bush forms monocultures in the beds and banks of waterways, rivers, floodplains, open woodlands and grasslands.
Bellyache bush is limited to certain areas of the country especially in the north and north east parts of the country. It’s very important to control those areas by relevant authorities of the country before they further spread and established monocultures.
Pictures and Text By , Dr. Lalith Gunasekera, Invasive Plant Specialist, Queensland - Australia