Erythrina herbacea

Two subspecies were recognized in this species: subsp. herbacea (SE USA) and subsp. nigrorosea (Mexico). Kartesz (1994) doesn't include these names as synonyms or provide distribution, and given that one is extralimital to his treatment, it is unknown if that concept includes material in Mexico. Therefore this record is interpreted as a equivalent of subsp. herbacea of earlier treatments (Krukoff 1982).

Erythrina herbacea is a shrub or small tree of the southeastern United States. It is wide ranging and common across the majority of its range.

Erythrina herbacea is endemic to the southeastern United States with the northernmost occurrence in Carteret County, North Carolina and the southernmost in Cameron Co., Texas. While there are specimens from Mexico, Nesom (2016) is clear that the species, as of 2016, is not known from Mexico. It is expected that his treatment has not yet been applied to existing records. The "Checklist of the native vascular plants of Mexico" was published in the same year as the revision of Erythrina herbacea (Nesom 2016), thus the newly revised entities were not likely evaluated by Villaseñor (Villaseñor 2016) who lists Erythrina herbacea as present in Mexico without indication of which subspecies are present. There are multiple occurrences skirting the US-Mexico border. Range extent was calculated with GeoCAT using occurrence and photo based observation data (GBIF 2022, iNaturalist 2022, Bachman et al. 2011).

Based on herbarium collections, photo-based observations, and field observations, there are likely over 300 occurrences rangewide (GBIF 2022, iNaturalist 2022, SE RSGCN Workshop 2022, Weakley and Southeastern Flora Team 2022). It is rare at the periphery of its range, including Arkansas (Soteropoulos, pers. comm., 2022).