Wonder Weed

Not all weeds are bad. Some actually contribute to the well-being of the environment in their own little ways, writes Elaine Yim

THE regarded as a widespread weed or pest plant, is listed as a noxious weed in the US and Australia. But here in this country, we can find it growing and blooming everywhere, especially along the roadside. Even though its little daisy-like flowers are quite pretty, not many people bother to take a closer look at them since they are so common.

Weeds are often regarded as bad for the environment because they can become very invasive to the extent that they threaten the survival of native species, compete with garden plants and reduce the yield of food crops. But this common weed actually contributes to a better environment in its own little way. Not only does it provide food for wildlife pollinators such as bees, moth, wasps, ants and other bugs, but it’s also a popular nectar food plant for many types of butterflies.

Some examples of these gorgeous butterflies are the Tawny Coster (Acraea violae), Crimson Tip (Colotis danae), Plain Tiger (Danaus chrysippus), Pea Blue (Lampides boeticus), Forget-menot (Catochrysops strabo), Common Gull (Cepora nerissa), Gram Blue (Euchrysops cnejus) and Striped Pierrot (Tarucus nara).

The leaves have medicinal properties and they’re used in Indian traditional and Ayurveda medicine.

Scientific research is ongoing on its application in curing many modern diseases. Now let’s get to know more about this wonder weed. THE PLANT

Tridax procumbens is an herbaceous perennial native to tropical America. It has become naturalised in many countries around the world in regions with tropical, sub-tropical, as well as mild temperate climates and is regarded as a weed or pest plant in many places.

The plant grows prostrate on the ground, creeping with long stems that can extend to more than 70cm long. These stems can form new roots at the leaf nodes. The simple leaves are green in colour, oval-shaped and alternately arranged.

Flowering occurs freely the whole year round. Members of the Compositae family bear composite flowers and each flower head is made up of many flowers; the ray florets and disc florets are packed densely together in rows around a centre.

The ray florets are those with conspicuous cream yellow bracts and they’re arranged on the outer circle while the inner rings comprise disc florets which are tiny flowers with tubular corollas. Each composite flower head is held up by a long, hairy stalk that can extend 30cm tall.

The fruit is called an achene. It contains only a single seed and doesn’t break open when ripe to release the seed. The achene is covered with long hairs and this feathery wing helps in the dispersal when carried by the wind to faraway places. Each plant can produce more than a thousand achenes, which explains its ability to self-seed hence its survival skill to become so invasive in certain areas.

IDEAL CONDITIONS FOR GROWTH

It grows as a weed along pathways, by the roadside, drain and wall cracks, rock crevices, fields, open areas and dumpsites. Not too fussy with soil requirements, it can flourish in sunny locations where the soil is dry and sandy. This weed that grows wild and free by the roadside is a nectar plant for many butterflies.