A SYSTEMATIC REVISION OF PHYLLANTHUS SUBSECTION URINARIA (EUPHORBIACEAE)

The examination of several taxa from various tropical regions of the world, previously classified as Phyllanthus urinaria L., indicates that they do not belong to a single species. On the basis of morphology, cytology, genetics, and biometry, a new classification is presented in which the collective species P. urinaria, or “urinaria complex,” is elevated to the subsection level: Phyllanthus subsection Urinaria. Within the subsection, two subgroups may be recognized on the basis of seed coat ornamentation. Each of these lines is represented by two species which differ from each other in chromosome number: P. embergeri nov. spec. (2n = 100) and P. nozeranii nov. spec. (2n = 50) in the “spiraled” line, P. hookeri Muell. Arg. (2n = 100) and P. urinaria L. (2n = 50) in the “radiated” line. In the latter species, which has undergone diversification, two subspecies may be distinguished: P. urinaria urinaria and P. urinaria nudicarpus subspec. nova.