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 americana Ficus americana Ficus americana, commonly known as the West Indian laurel fig or Jamaican cherry fig, is a tree in the family Moraceae which is native to the Caribbean, Mexico in the north, through Central and South America south to southern Brazil. It is an introduced species in Florida, USA. The species is variable; the five recognised subspecies were previously placed in a large number of other species. "Ficus americana" is a shrub or tree which grows up to 30 m (100 ft) tall. With about 750 species, "Ficus" (Moraceae) is one of the largest angiosperm genera (ranked the 31st