| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Asteraceae | Tetragonotheca helianthoides | Squarehead, Pineland-ginseng | Longleaf pine sandhills, sandy woodlands, open hammocks, calcareous glades, alluvial sand barren grasslands, roadsides. | Se. VA and e. TN south to c. peninsular FL and s. MS. |  |
| Asteraceae | Tetragonotheca ludoviciana | Louisiana Square-head | Sandy pine and mixed woodlands. | Se. AR and nc. TX south to sw. LA and se. TX. |  |
| Asteraceae | Tetragonotheca repanda | Showy Nerve-ray | Sandy soils. | S. TX. | |
| Asteraceae | Tetragonotheca texana | Texas Squarehead | Calcareous prairies and other uplands. | TX south into Mexico (CHH, COA, NLE, TAM). |