Buddleja vexans is a recently (2000) recognized species endemic to central Peru, growing along streams, roads and cliffs at altitudes of 3,300 - 3,900 m. Norman adjudged the plant to be a probable hybrid between B. coriacea and B. incana.[1]
Buddleja vexans is a sterile shrub 3 - 5 m high with a trunk < 30 cm in diameter, the bark brown and fissured. The younger branches are terete and tomentose, bearing coriaceous elliptic leaves 4.5 - 8 cm long by 1 - 3 cm wide, glabrous and rugose above, densely tomentose below. The fragrant golden-orange paniculate leafy-bracted inflorescences are 5 - 12 cm long by 5 - 9 cm wide, comprising 1 - 2 orders of branches bearing heads 1.5 - 2 cm in diameter, each with 16 - 20 flowers, the corollas 4 - 5 mm long.[1]
A popular garden plant in Peru, Norman considers B. vexans to have the greatest horticultural merit of all the American buddlejas.[1]
The shrub is not known to be in cultivation beyond Peru.