| Author | (A. Gray) J.D. Sauer | |
| Distribution | Outer Coastal Plain and Outer Banks only. The species' northern limit is in southeastern VA.
Native of the Gulf Coast and southward to northern S.A. Adventive on the Atlantic Coast. | |
| Abundance | Rare to uncommon, but local. | |
| Habitat | Margins of brackish marshes, tidal creeks, interdune swales. | |
| Phenology | Flowering and fruiting May-August. | |
| Identification | Southern Water-hemp is much like the more common Saltmarsh Water-hemp (A. cannabinus), but may grow even taller -- plants on Ocracoke Island (Hyde County) can reach 11 feet tall! Technically, the floral bracts are more than 1 mm long in A. australis versus less than 1 mm long in that native species, and the bract midribs are usually strongly projecting (vs. scarcely so in A. cannabinus). | |
| Taxonomic Comments | | |
| Other Common Name(s) | | |
| State Rank | SE? * | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
