Gonzales County, where it appears to be extirpated; L. E. Brown and S. J. Marcus 1998); it is widespread in the American tropics. Like P. urinaria, it is widely used in folk medicine and is the subject of intense pharmacological research. Plants from outside the West Indies and Caribbean northern South America often have been segregated as subsp. lathyroides; the differences are trivial and recent authors (G. L. Webster 2001; V. W. Steinmann 2007) did not subdivide the species.http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220010364
Some of key differences in Phyllanthus amarus and Phyllanthus niruri
- Leaf apex
- Arrangement of male & female flowers
- glands
-leaf apex is slightly pointed in amarus but completely round in niruri
-Male flowers are at the base then male and females from the same node but different stalks and then female flowers are the top, whereas in niruri male flowers are the top and females are at the top.
-Lobed glands in amarus but unlobed in niruri