Rediscovery of Quercus aliena Blume (Fagaceae) in Taiwan

The first collection of Quercus aliena Blume var. acutiserrata Maxim. ex Wenz. in Taiwan was made by Y. Shimada in 1924 from Hongmao. Since then, no other specimen had ever been collected. Recently, this species was rediscovered from Fengshan (3 km south of Hongmao) in Hsinchu County. On closer studies it was found to be the typical variety of Q. aliena Blume rather than the name recognized by Shimada. The population of Q. aliena is quite small at that limited location, and is vulnerable to human impacts. Therefore, it is necessary to take steps to conserve the habitat as soon as possible. The taxonomic treatment, morphological descriptions, photographs and notes of the species are given here. A key to distinguish it from the other three closely related Taiwanese species is also provided