photo by Alan Cressler, obtained from Lady Bird Johnson Wildflower Center (wildflower.org), described as an unrestricted image (educational and scientific use)
Recently discovered in a far-northern Mississippi County, this extremely rare (S1, G1) sunflower species was previously known only in Georgia, Alabama, and Tennessee. Whorled sunflower is considered a narrow habitat specialist occurring in wet prairies and calcareous barrens.
From the USFWS Species Profile (ECOS Environmental Conservation Online System) Whorled sunflower is found in moist-soiled sites where little to no overstory canopy is present. Habitat quality ranges from remnant prairie or woodland sites to degraded sites along roadsides, railroad tracks, and agricultural fields. Despite their commonly degraded condition, associated plant species in these habitats indicates a community with strong prairie affinities
Distribution map from Biota of North America Program: