The city zoo has decided to initiate steps to protect a rare Arara nut-tree on its verdant premises. A medium to tall tree with a wide canopy, it belongs to the Euphorbiaceae family, the same as that of the rubber tree. In Kerala, the Arara nut-tree is known to be found only in the Thiruvananthapuram zoo. There are no details available in the Thiruvananthapuram zoo and museum archives on this tree, says botanical garden superintendent Vijayalakshmi P.V. In fact, it appears that in all the years it has been standing there only one another Arara nut-tree has managed to take roots and grow.