Surely one of the most surreal sights one can witness while walking through the forest is the Indian Coral Tree. Leafless in winter, the tree takes on a ghost like appearance with its light grey almost white bark, disappearing and reappearing through the evening mist. The trees appearance takes an even more macabre turn when in early summer it sprouts scarlet buds that are needle like and resemble the blood drenched claws of some otherworldly beast. However, when these buds bloom and the tree is covered in delicate flowers it looks like it bears a resplendent, ruby crown.
Numerous Birds flock to feast on these blossoms these include; Mynahs , Drongos, flowerpeckers and sunbirds. Another common visitor is the Vernal Hanging Parrot that feeds on the flowers while hanging upside down; the green feathers of the small bird contrasts beautifully against the bright red of the tree in bloom. A similar play of colours can be seen when Parakeets alight on the tree but they come in flocks of up to six or seven individuals at a time and briefly there is a pleasant noisy confusion as the birds gossip while they eat.
Woe to the weary traveller who decides to use this tree as a rest stop though. The pale bark is lined with rows of curved spines. These spines however make the tree very hospitable towards vines and creepers. This fact is often taken advantage of by farmers who use this tree to grow pepper, vanilla and betel vines.
The tree is very fast growing and can be propagated by simply planting a freshly cut branch into the ground. The broad leaves which grow back in the latter, hotter part of summer provide shade and when the rains begin, they provide shelter. These leaves are then shed during winter when shade and shelter are no longer required and on the ground, they act as mulch which protects the ground from desiccation during the dry months. In addition to this the leaves enrich the soil with vital nutrients when they decompose.
The Indian Coral belongs to the leguminous family of plants. This family possesses a unique ability, that of nitrogen fixation. The tree forms a symbiotic relationship with a group of bacteria known as Rhizobia. It is these bacteria that actually fix the nitrogen and the tree in return furnishes for the bacteria, living quarters in the form of root nodules, and provides the bacteria with nutrients such as sugars and other compounds. Nitrogen fixation is a process by which atmospheric nitrogen is made available for use by living organisms. Fixing by soil bacteria is one of two means by which this is accomplished the other being lightning strikes which break the inert nitrogen molecules allowing them to then dissolve in rain water. This fixed nitrogen is then made available to be utilized by other plants when the leaves are shed and broken down in the soil.
The flowers are mostly pollinated by birds and soon turn into pods. The fleshy parts of the pod are consumed by many animals, especially arboreal mammals. The seed however is ignored and not eaten by anything as it is toxic. Therefore, if the seed is not dispersed by some animal that has perhaps, carried a pod some distance away from the tree then its only option is to fall to the ground directly below the parent tree. This would be fine; however, the tree does not do well in shade and hence grows poorly under its mother’s canopy. So, the tree has evolved an ingenious strategy to combat this problem it has evolved to grow nearby water bodies like streams and lakes and sometimes even beside the sea shore. The tree can withstand high moisture levels in the soil and can even survive in waterlogged conditions. By doing this the tree ensures that at least some of its seeds are dispersed by water. The seeds too have evolved for this as they float and are resistant to salt water. By travelling through water in this manner the tree has colonized many of the areas in its range. Surprisingly this tree which grows near water bodies and is typically found in areas with moderate to high levels of rainfall can also endure periods of drought like condition for months at a time.
So this forest beauty, in addition to serving highly important ecological functions is also a truly versatile wonder.
(About the author: Sagar is an aspiring writer and an avid nature enthusiast. He has a degree in Chemistry, Environmental Science and Zoology. He has been part of survey of amphibian diversity in aggro forests of Karnataka’s Western Ghats, conducted several awareness talks on identification of common snakes and role of reptiles in the ecosystem)
FLOWERS OF INDIA- Erythrina variegata-Indian Coral Tree www.flowersofindia.net
ARUNACHALA LAND- Erythrina Indica-Coral Tree arunachalaland.blogspot.com
Tropical Plants Database, Ken Fern. tropical.theferns.info. <tropical.theferns.info/viewtropical.php? id=Erythrina+variegata>