<i>Curcuma sirirugsae</i>, a New Species of the family Zingiberaceae from Northern Thailand

Abstract

he aim of this study was to describe a new species of the genus Curcuma L. (Zingiberaceae) from northern Thailand. It has been named  Curcuma sirirugsae Saensouk & Rakarcha and its description, illustrations, and photographs have been provided. The new species  belongs to the subgenus Curcuma and is identified by its two downward-facing spurs, presence of coma bracts, closed flower form and  epigynous glands. Curcuma sirirugsae is endemic to the Sukhothai Province in northern Thailand. The morphology of C. sirirugsae and C.  angustifolia Roxb. are quite similar, but there are distinct differences in the following characteristics: the leaves are broadly elliptic, the  fertile bracts are ovate to lanceolate and densely arranged with an acute apex, they are also pubescent. Additionally, the coma bracts are  larger, pubescent, and have an acute apex. The lateral staminodes are irregularly oblong to irregularly elliptic, and the anther spur is longer. Details on the description regarding morphological characteristics, including distribution, ecology, phenology, vernacular,  etymology and preliminary conservation assessment are provided. It also includes an updated key to the 25 species of the Curcuma  subgenus Curcuma recognized in Thailand, as well as an investigation of its closest species.