Mimosa distans and M. neuroloma, here more closely associated as varieties of M. distans, were first described, each from few collections, as members of ser. Meticulosae ***Semistrigosae, and M. neuroloma was confused, in the first instance, with M. meticulosa Martius, which Bentham later found to be something else (exactly what is even today unknown). Bentham admitted to difficulty in distinguishing these two species, and the difficulty has not been dissipated by modem collections. In his monograph Bentham (1875, 1876) transferred M. distans to ser. Pedunculosae, stating (1876: 326) that despite nearly dimidiate leaflets it was readily distinguished from M. neuroloma, retained in ser. Meticulosae, by form of inflorescence, meaning, it seems, by relative length and arrangement of the peduncles. It is no longer possible, however, to separate two credible species by peduncle-length or by prevalence of strictly axillary longer peduncles over pseudoracemose shorter ones. Shifting emphasis to length and proximity along the stem of cauline leaves, length of leaf-stalks and girth of setae on leaflet-margin, each to some degree individually variable, it is possible to maintain two taxa, but only at the varietal level.