This work reports a systematic comparative study of the technological properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particle sizes and distributions were quite similar with an average diameter around 1 mu m. Molecular weight, Wallace plasticity, and Mooney viscosity values were approximately the same for both rubbers. Fourier transform infrared spectroscopy peaks characteristic of natural rubber were observed for both Hancornia and Hevea. The measured differences in technological properties included lower values for Hancornia dry rubber content, % ash, % nitrogen, and plasticity retention index but higher value for acetone extract. Interestingly, nitrogen and protein content were much lower in Hancornia, suggesting that it may have important applications in nonallergic rubber uses. This represents the first report of lacticifer-produced low-protein natural rubber. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 2986-2991, 2009