Buddleja microstachya is a small shrub discovered in 2005 by Liu and Peng in Yunnan, China, growing at an elevation of 3,200 m in rocky terrain of the Yongde Mountains Nature Reserve.[1] First described in 2006, this putative species was not included in Leeuwenberg's study of Asiatic and African buddleja published in 1979.[2]
Buddleja microstachya grows to 1 - 2 m in height in the wild. The branchlets are quadrangular and densely tomentose, the bark of old branches peeling. The leaves are lanceolate, 1.5 - 5.0 cm long by 0.5 - 1.3 cm wide, tomentose above, densely tomentose below. The small terminal inflorescences consist of two or three flowers forming a cyme, several cymes forming a compact panicle. The corolla is lavender to white, cylindrical, 4 - 6 mm long and densely tomentose outside.[1]
Buddleja microstachya most closely resembles B. yunnanensis but differs in flower morphology and has a very isolated range, whereas B. yunnanensis has a wide distribution.
Buddleja microstachya is not known to be in cultivation.