| Author | L. | |
| Distribution | Mostly in the Coastal Plain and Sandhills, scarce in the Piedmont and Mountains. Apparently absent from the northeastern portion of the Coastal Plain.
Native of South America; in N.A. NJ to IN south FL and TX. | |
| Abundance | Frequent in the central and southern Coastal Plain and Sandhills, but rare elsewhere. | |
| Habitat | Dry sandy soil of roadsides, ditches, cropfields, sandhills, campus weed, yard weed, dump. | |
| Phenology | Flowering and fruiting June-October. | |
| Identification | Rough Mexican-clover is very similar to R. brasiliensis, which see. It differs by the leaves which are hairy only on the midrib and margins (vs. hairy on both sides across the whole surface). The stem in this species is hirsute only near the tips, but mostly glabrate to progressively less hairy toward the base; R. brasiliensis has the stems quite hirsute throughout their length. | |
| Taxonomic Comments | | |
| Other Common Name(s) | | |
| State Rank | SE? * | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
