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 subgenus "Sycomorus", and the species of subgenus "Ficus", though the relationships of the sections of these groups to one another are not well resolved. Subgenus "Ficus" Subgenus "Pharmacosycea" Subgenus "Sycidium" Subgenus "Sycomorus" Subgenus "Synoecia" Subgenus "Urostigma" Unknown subgenus Numerous species of fig are found in cultivation in domestic and office environments, including: Fig trees have profoundly influenced culture through several religious traditions. Among the more famous species are the sacred fig tree (Pipal, bodhi, bo, or po, "Ficus religiosa") and the banyan fig ("Ficus benghalensis"). The oldest living plant of known planting date is a "Ficus religiosa" tree known as