Sida spinosa L. (Malvaceae), a Newly Naturalized Plant in Taiwan

Sida spinosa L. is native to Tropical America, now naturalized to central and southern Taiwan. A taxonomic treatment, line drawing, and color photographs of this species from wild are provided to aid in identification. The morphology of S. spinosa L. is very similar to S. acuta Burman f., and is distinguished from features of stems, leaves and mericarps.