One Sunday morning, I bought a local (indian) yellow-flowered climber and was looking around for a stick to support it. A discarded piece of wood not far away caught my eye and I stuck it in the pot and trained the climber over it.
A few weeks later, I saw that piece of wood sprouting leaves! Not only that, it soon started flowering and butterflies were all over it, pollinating it. The little yellow climber did not stand a chance. The nasty usurper was a very pretty lantana.
The truth about these beauties
Lantana camara, a native of the Americas (and hence a foreign plant in India), is very hardy and finds a way to survive, growing even from an old stick. And so it is with some species that are introduced in places where they don’t belong. These plants could be introduced deliberately (in gardens or ponds as ornamental and exotic specimens) or by accident (seeds among sacks of grain).
Once such a plant reaches a new place, it competes with local plant species, competes for pollination and establishes itself in the ecosystem. Such aggressive species are called “invasive” and are mighty difficult to get rid of once they take hold. They don’t require any particular type of soil or much water – anything will do. This “generalist” – a non-fussy plant – is a survivor and thrives in its new home.
Another invasive pest is the lovely violet-flowered water hyacinth. Introduced from S. America as an ornamental plant, it quickly spreads over water surfaces crowding out any local reeds and depleting the amount of oxygen in the water. Precious lakes and rivers are depleted of water and the fish in it suffer as well.
It costs over $140 billion in the United States and to the tune of $1.4 trillion worldwide to control invasive plants and animals annually. This includes eradication, water purification due to invasive algae and water plants like hyacinth, and loss of crops. More importantly, many local plants are sources for medicines are lost when such mass infestations occur.
Prevention and vigilance help
Prevention is the best cure in this case. Gardens and ponds are best off having native species in them. However, given the global nature of trade and transport today, species are traveling around the world faster than ever before. Being vigilant and (literally) nipping the problem in the bud is our best bet!