Nicotiana attenuata — A plant with four lives!
The plant is also known as Wild tobacco or Coyote tobacco and is native to western North America and northern Mexico. These plants grow well in these regions. They are widely used for various medicinal purposes and for smoking by the Aborigines in North America. Nicotiana attenuata has been recently studied by many plant biologists and chemists and the observations blew their mind which you’ll read here and get your mind blown!
Kingdom : Plantae
Division : Angiosperms
Sub-division : Eudicots
Class : Asterids
Order : Solanales
Family : Solanaceae
Genus : Nicotiana
Species :N. attenuata
The plant is a small annual herb that reaches a maximum height of 1 metre. It is sparsely haired and glandular. The leaves are arranged rosulate and are broader at the base and narrower towards the top. The leaves are petiolate. The flowers are long tubular about 2 to 3 centimeters in length and are greenish white. The leaves are borne in green and sharp sepals.
Nicotiana attenuata has been widely used by the native people for various medicinal purposes and smoking. They smoked this plant ceremoniously. The leaves of N. attenuata were picked, dried and greased. After this, the leaves of bear berry plants are collected, dried and made into a powder. They smoked the leaves of N. attenuata mixed with the crushed dried bear berry leaves.
Now, here comes the interesting part!
The plant has a variety of defences against its enemies. First, it comes with its innate defence. The plant has high concentrations of nicotine which is poisonous to most of the animal and insect species. The nicotine is produced in the roots and accumulated in the leaves. This protects the plant from voracious herbivores and other insects. Nicotiana attenuata tobacco is found to contain as much as three times more nicotine concentration compared to normal tobacco plant.
The Hawk Moths are seriously important for the survival of this plant. This moth is an effective pollinator of the wild tobacco plant. The plant relies on this moth greatly for its pollination. The moths are generally nocturnal and so the plant blooms only during the nights in order to facilitate pollination by the moth. But, the cunning moth claims huge price from the plant for its services. As the moth visits each plant, it lays its eggs on it. The eggs then hatch into caterpillars and start devouring the plant. These little buggers are resistant to nicotine and start growing well on this plant.
Call for Help
The plant made a terrible decision by choosing these moths as its pollinator. But, its never too late to mend! The plant has a plan B to solve this issue. As the attack of the caterpillars increase, the plant releases volatile compounds in air. These volatile chemicals attract the bugs called Geocoris which feed on the caterpillars and eggs of the hawk moths. This chemical signal also induces other plants around it to release the same alarm signal. This is triggered by the oral secretions of the caterpillars.
Sometimes, friends may not be available for the plant at the right time or there may even be too much attack that the Geocoris bugs cannot handle. This time, the plant has a second plan. It gets ready to face the caterpillars itself!
The plant secretes a juicy sweet liquid from its trichomes which are irresistible to the caterpillars and they readily consume the sweet liquid. The dumb caterpillars don’t know the sinister plans of the plant! They eat the nectar and they wiggle around in it and now the plan worked! The caterpillars all smell like nectar. This would now attracts more predators who have not noticed the plant’s previous call. The nectar has two purposes indeed. One is to make the caterpillars smell like delicious lemon pies to its enemies. The second is it contains a chemical enzyme that would slow down the caterpillars digestion, thereby reducing its metabolism. This in turn makes the caterpillar eat less and the plant would feel quite safe until the caterpillar becomes a prey to one of its predators!
A New Welcome Party!
The plant has worked so much to avert these caterpillars to save itself. A single Hawk Moth is able to lay an astounding 200 eggs and there would be a dozens of these moths visiting each plant. So much eggs would turn into a judgement day for the Wild Tobacco plant. When everything gets too bad that the plant cannot take more, it does not give up! It gives another big surprise by switching its pollinators. These plants are capable of switching their pollinators! The plant suddenly stops blooming at night and the flowers start blooming during the day. The flowers in the day attract Humming Birds which pollinate the flowers. The plant is capable of switching its flowering cycle from night to day in just 8 days.
Though the plant switches its pollinators to Humming Birds, it seems that Hawk Moths are a better choice for them. The plants again switch back to night flowering as they are rid of the caterpillars. But, all together this plant has some fascinating ways to live its life and teaches us to never give up as problems bug us like the caterpillars bug the plant.
Original post from happybotanist.com — http://www.happybotanist.com/flowering-plants/dicots/solanaceae/nicotiana-attenuata