They stand tall amid the destruction — thousands of palmyra trees in Nagapattinam, Thanjavur and Tiruvarur districts have withstood the force of Cyclone Gaja, while pretty much all other kinds of trees, network towers and electricity poles have been uprooted and roofs of homes blown away.
Explaining how these trees were able to hold out against such extreme weather events, M. Narasimhan, former head of the Department of Botany at the Madras Christian College, said, “Three factors contribute to the survival of palmyra trees: First, the root system, though fibrous, has a strong grasping capacity. Second, the vascular system of the stem makes the tree flexible. Third, the crown of the tree. The folded leaves and structure help it withstand strong winds.”
Head weight factor
Of course, a few palmyra trees have fallen. But the strong winds during the cyclone, which were able to break coconut trees into two or three pieces, weren’t able to inflict similar damage on the palmyra tree — the State tree of Tamil Nadu. In ancient times, it was the official tree of the Chera Kings.
“There is a saying in Tamil: thalaiakanam illavittal ethaiyum samalikkalam (If you do not have head weight, you can survive difficult times). In the case of palmyra, the head is not heavy. I noticed that during Cyclone Thane in 2011, they were able to survive,” said Mr. Narashimhan.
Their endurance drives home the importance of planting more palmyra trees. “Wherever palmyra grows, one can vouch for the availability of ground water because its roots penetrate deep,” Mr. Narashimhan added.
Dr P. Ravichandran, Head of Department, Plant Biology, Manonmaniam Sundaranar University, told The Hindu that the unique features of the canopy, stem and roots of the tree gave it the strength to withstand calamities. He said the top crown or canopy was not so heavy in palmyra trees, when compared to coconut trees.
“The roots are fibrous and establish [themselves] 5 ft radially around the base and 5 ft-10 ft deep in the soil, and cannot be easily uprooted,” said Dr. Ravichandran, who has carried out extensive research on palmyra trees.
He said the wood was highly variable in weight, strength and hardness as it was so non-homogenous.
“The density of the wood is highest towards the outer wall of the trunk due to highly lignified fibro vascular bundles, and gradually becomes lighter, softer and weaker towards the soft core. As the outer [layer of] wood is hard and flexible, it can tolerate high wind velocity and may not break easily,” he explained.