The rubber-tree is native to Bolivia and to the Amazon Basin in Brazil. It reaches a height of 100 feet, with a trunk 2 feet in diameter. The leaves have a very long petiole and three leaflets, each up to 15 inches long. Flowers are minute but are grouped in large terminal inflorescences. Fruits are composed of three joined globular capsules, each with a seed approximately 1 inch long. It flowers during winter and spring, fruits mature during summer and autumn. The sap of this tree is the main source of natural rubber, being Malaysia its main producer. The generic name derives from the Brazilian common name for the tree. The species name refers to its geographic origin.

The photographed trees are part of a group of twenty-three specimens planted west of the Dispensary. There’s a larger tree southwest of the Chancellor’s house. All were planted by Henry Cowles.

Hevea brasiliensis (Euphorbiaceae)