Natural rubber at least showed promise as rubber sources, include the rubber fig ("Ficus elastica"), Panama rubber tree ("Castilla elastica"), various spurges ("Euphorbia" spp.), lettuce ("Lactuca" species), the related "Scorzonera tau-saghyz", various "Taraxacum" species, including common dandelion ("Taraxacum officinale") and Russian dandelion ("Taraxacum kok-saghyz"), and perhaps most importantly for its hypoallergenic properties, guayule ("Parthenium argentatum"). The term gum rubber is sometimes applied to the tree-obtained version of natural rubber in order to distinguish it from the synthetic version. The first use of rubber was by the indigenous cultures of Mesoamerica. The earliest archeological evidence of the use of natural latex from the
Ficus racemosa Ficus racemosa Ficus racemosa (syn. Ficus glomerata ) is a species of plant in the family Moraceae. Popularly known as the cluster fig tree, Indian fig tree or goolar (gular) fig, this is native to Australia, Malesia, Indo-China and the Indian subcontinent. It is unusual in that its figs grow on or close to the tree trunk, termed cauliflory. In India, the tree and its fruit are called "gular" in the north and "atti" in the south. The fruits are a favourite staple of the common Indian macaque. It serves as a food plant for the caterpillars of the two-brand