Buddleja cuspidata is a species endemic to Madagascar, where it grows along river banks. The species was first named and described by Baker in 1895.[1]
Buddleja cuspidata is a shrub 3 - 4 m in height, with brown tomentose branchlets, obscurely quadrangular. The opposite, thinly coriaceous leaves' blades are ovate or elliptic, 9 - 20 cm long by 4 - 9 cm wide, acuminate at the apex, decurrent into the petiole, sparsely pubescent above, brown tomentose beneath; the margins serrate-dentate to crenate-dentate. The narrow yellow inflorescences are axillary and spicate, 3 - 15 cm long by 1 - 1.5 cm wide; the corollas 7.5 - 8.5 mm long.
Buddleja cuspidata is considered closely allied to B. axillaris and B. sphaerocalyx.[2]
Buddleja cuspidata is not known to be in cultivation.