Weed Paradise: World heritage listed central highlands of Sri Lanka – Part 5

It is a neo-tropical plant widely distributed in its native South America from Panama, Colombia, Peru, and Brazil to Argentina. Suddha is not present in Australia and target weed under the Biosecurity Act 2015.


by Lalith Gunasekera

Suddha

Suddha plant (AUSTROEUPATORIUM INULIFOLIUM)

( October 17, 2017, Queensland, Sri Lanka Guardian) This species is commonly named as “SUDDHA” in Sri Lanka and similar appearance to podisinghomaran or siam weed (Chromolaena odorata) belongs to the same plant family Asteraceae but mainly grows at higher elevations (Central highlands of Sri Lanka).

Pic 1: Suddha plant flowering

It is a neo-tropical plant widely distributed in its native South America from Panama, Colombia, Peru, and Brazil to Argentina. Suddha is not present in Australia and target weed under the Biosecurity Act 2015. Suddha plant is a perennial, spreading scrambling shrub grows up to 2-5 meters tall. Stems covered with dense short hairs and moderately branched. Leaves are simple and opposite below becoming sub opposite or alternate above. Leaf petiole is 1-2 cm long, leaf blades are ovate to narrowly oblong, 7-14 cm long, 2-8 cm wide, margins are serrate, and 3 veined starting from well above base, hairy, pale green beneath. Flowers are terminal or arising from upper nodes. Flower head comprising 3-4 series of bracts enclosing 10-15 creamy white florets with corollas 4-5 mm long, flowers fragrant. Seeds are oblong with a whitish pappus 4 mm long. Seeds are spread by wind, water, animals, humans and vehicles.

This plant has been spreading mainly in central highlands of Sri Lanka smothering most of native and useful endemic plants.

Popcorn cassia

Popcorn cassia (SENNA DIDYMOBTRYA) is being spread in knuckle mountain range especially between Hunnasgiriya- Mee muray roadside and forest areas as well as in Nuwara Eliya area. This plant species originated in Central Africa and introduced to
Sri Lanka through horticultural industry as a garden ornamental

Pic 2: Popcorn cassia – flowers, pods and leaves

It is usually a several stemmed, hairy, aromatic shrub or tree grows up to 9 m tall. The plant has a strong scent which has been variously described as being reminiscent of mice and peanut butter. The plant flowers plentifully in racemes bright yellow flowers with some flowers also occurring in leaf axils. The flower raceme has open flowers on the lower part with unopened buds at the tip covered in stark brownish green or black bracts.

Pic 3: Growing along in tea growing area of Talawakelle

The flower has five concave petals each 1.5 – 3 cm long. The flower has ten stamens, usually seven fertile ones and three sterile staminodes. Some of the stamens have large anthers measuring a centimeter long. The fruit is a flat brown legume pod up to 12 cm long which contains up to 16 bean like seeds up to a cm long.

Wild Tobacco Tree

Wild tobacco tree (SOLANUM MAURITIANUM) is highly invasive environmental plant originated in Argentina. The plant has spared in Sri Lanka, South Africa, Uganda, USA, Australia, New Zealand and Polynesia

Pic 4: Wild tobacco plant

Plant has oval shaped leaves, upper surface is green and sparsely hairy. Lower surface is grey or fawn, densely hairy and sharply pointed tips. The flowers are numerous in flat topped clusters to about 15 cm diameter at tips of branches. Flower has 5 petals with violet colour. Fruits are berries, round, green and turning dull yellow when mature. Large number of seeds are produced by the plant. Seeds spread by water, birds, humans and vehicles.

I have noticed that the wild tobacco plant has been spreading along the road to Horton Plains from Ambewela, Bogawantalawa, Pinnawela as well as Knuckles mountain range. This plant can tolerate shade and moderate drought once established. It can invade grassy woodlands, damp and wet forests, gullies and other moist sites in both disturbed and intact native vegetation, rainforest edges, roadsides and pasture. Wild tobacco plant is a real threat to our world heritage central highlands. Look out!

Mexican Elder

Mexican elder or black elder (SAMBUCUS NIGRA) is originated in Europe and introduced to Sri Lanka as an ornamental species mainly in Central Highlands of Sri Lanka. It is a small tree growing up to 4-6 m (rarely 10 m) tall.

Pic 5: The Mexican elder tree and flowers

The stem of the plant is light grey when young, but changes to a coarse grey outer bark with length wise furrowing when mature. The leaves are arranged in opposite pairs, 10-30 cm long, pinnate with five to seven leaflets. The leaflets are 5-12 cm long and 3-5 cm wide with serrated margin.
The flowers are borne in large corymbs, 10-25 cm diameter, produced in drooping clusters in the late autumn. They are an important food source for many fruit eating birds and spread throughout the area. When you visit in central highlands of Sri Lanka, you will be able to notice the plant spreading in the area especially at Nuwara Eliya and surrounding areas.

To be continued


Dr. Lalith Gunasekera is an invasive Plants Specialist lives in Mackay – Queensland

Author: Sri Lanka Guardian

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