Taxonomic changes regarding three species of Zingiber (Zingiberaceae) from Thailand

Zingiber teres S. Q. Tong & Y. M. Xia and Z. xishuangbannaense S. Q. Tong are reduced to be synonyms of Z. smilesianum Craib and Z. thorelii Gagnep., respectively. Z. cochinchinense Gagnep. is changed to be a subspecies of Z. zerumbet (L.) Sm.