【Objective】 In Strobilanthes, several species exhibit the plietesial phenomenon that plants grow for many years, flower gregariously, and then die, in the same manner as bamboos. Strobilantes retusa was described based on materials collected from a Karst area in Huangjiang, Guangxi and the variation in morphology is poorly understood because of the limited material available. The discovery of this species in the Maolan National Nature Reserve of Guizhou Province is of great significance for studying the flowering mechanism of plietesial species. 【Method】 The morphological characters and flowering habits of S. retusa were observed in the Guizhou population, and the morphology of pollen and seeds was observed using scanning electron microscopy. 【Result】 S. retusa is restricted to Karst areas at the border of Guangxi and Guizhou, and is newly recorded in Guizhou Province. Pollen grains are prolate and 3-colporate with 12-15 pseudocolpi, and possess undulate exine ornamentation. Seeds are ovate in outline densely spirally multicellular with large areolae. 【Conclusion】 S. retusa is a plietesial species with a presumed life circle of 7-10 years. The affinity of S. retusa is discussed, and the supplementary morphological description, line drawing, and color photographs are also provided.