MEXICANUM [Britton, 1899] Cent. America, growing high up on volcanos, n=18, this odd species has no known relatives in the New World, but seems closest to some in eastern Asia (according to botanist Uhl). It may be in section Orientalia, though it is not found wild in the Orient, thus it presents a mystery. Its species name refers to Mexico, but even this is in total error. It was learned that it was first found by botanists growing in cultivation in Mexico City, thus the name; but it is found wild only in Central America. It is of easy culture and is grown widely in gardens in warm climates, but it survives frost and has naturalized in parts of south Europe. This is the only yellow flowering sedum with leaves in whorls of 4. This fact serves to identify it. [Note: Some nurseries sell another sedum under this name, but it is unrelated: it has white flowers and is called the “Spiral Staircase” and is probably some odd hybrid, but is vigorous growing and popular in nurseries for sale under this wrong name].