Taxonomy and Systematics
The taxonomy and systematics of the many dozens of Desmodium species are extremely confusing and far from resolved. Related genera such as Codariocalyx, Hylodesmum, Lespedeza, Ohwia and Phyllodium were and sometimes still are included in Desmodium.
Many of these plants being rather small, inconspicuous and nondescript, the same taxa have been applied to what later turned out to be very different species. For example, D. spirale as described by August Grisebach might refer to a distinct species but its validity is doubtful; the "D. spirale" of other authorities may refer to either of D. neomexicanum, D. ospriostreblum or D. procumbens. Similarly, the plant originally described as D. podocarpum by A. P. de Candolle is Hylodesmum podocarpum today, but "D. podocarpum" might also mean D. hookerianum or Hylodesmum laxum, depending on the taxonomic authority.
Read more about this topic: Desmodium