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
Origin of the Romanians preservation or lack of certain Latin terms reveal that Romanian developed north of Lower Danube. One of these terms is the Latin word for gold "(aurum)", preserved in Daco-Romanian, but lost in Aromanian and Istro-Romanian. For Nandriș, the word is important evidence for the Romanians' continuous presence in Transylvania, because Romanian mountainers owned many Transylvanian gold mines in Modern Times, and Nandriș thinks that newcomers would not have been allowed to open mines in the province. The Latin terms for fig tree "(ficus)" and chestnut "(castaneus)" were kept in Aromanian and Megleno-Romanian, but they disappeared from Daco-Romanian. Nandriș and Sala