The species Passiflora biflora Lam. (Passifloraceae), native to Central and South America, has naturalized at low altitudes in northern Taiwan. It can be distinguished from the other congeners found in Taiwan based on its broad obreniform leaves with ocelli on both surfaces, yellow coronal filaments, and seed surface with transverse ribs. Morphology and photographs of P. bi-flora, as well as a key to Passiflora species in Taiwan have been provided to facilitate for identification.