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 elastica Ficus elastica Ficus elastica, the rubber fig, rubber bush, rubber tree, rubber plant, or Indian rubber bush, Indian rubber tree, is a species of plant in the fig genus, native to eastern parts of South Asia and southeast Asia. It has become naturalized in Sri Lanka, the West Indies, and the US State of Florida. It is a large tree in the banyan group of figs, growing to (rarely up to ) tall, with a stout trunk up to in diameter. The trunk develops aerial and buttressing roots to anchor it in the soil and help support heavy branches. It