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 verruculosa Ficus verruculosa Ficus verruculosa, the water fig, is a species of fig from sub-saharan Africa. It is found from north eastern South Africa, northern Botswana and Namibia to Uganda and west to Nigeria in riverine and swamp fringes or grassland, always near water. It is pollinated by the wasp "Platyscapa binghami". The growth form of "Ficus verruculosa" is as a shrub, or weak-stemmed, sparsely branched shrub 0.2-0.6 m tall, less often a small tree up to 12m, often forming low, creeping thickets. Leaves oblong to lanceolate, 3.5-20 x 1.5-8.5 cm, leathery, hairless. Figs are produced mostly in pairs in leaf