| Thysanocarpus laciniatus subsp. desertorum (A. Heller) Abrams, 1944 |
| Thysanocarpus laciniatus var. affinis (Greene) Munz, 1932 |
| Thysanocarpus laciniatus var. emarginatus (Greene) Jeps., 1925 |
| Thysanocarpus laciniatus var. eremicola Jeps., 1936 |
| Thysanocarpus laciniatus var. hitchcockii Munz, 1932 |
| Thysanocarpus laciniatus var. ramosus (Greene) Munz, 1932 |
| Thysanocarpus laciniatus var. rigidus Munz, 1932 |
| Thysanocarpus oblongifolius Nutt. ex Torr. & A. Gray, 1838 |
| Thysanocarpus pulchellus Fisch. & C.A. Mey., 1835 |
| Thysanocarpus pusillus Hook., 1836 |
| Thysanocarpus ramosus Greene, 1887 |
| Thysanocarpus rigidus (Munz) P. J. Alexander & Windham, 2010 |
| Thysanocarpus trichocarpus Rydb., 1903 |
| Tomostima Raf., 1825 |
| Tomostima cuneifolia (Nutt.) Al-Shehbaz, M. Koch & Jordon-Thaden, 2012 |
| Tomostima platycarpa (Torr. & A. Gray) Al-Shehbaz, M. Koch & Jordon-Thaden, 2012 |
| Tomostima sonorae (Greene) Al-Shehbaz, M. Koch & Jordon-Thaden, 2012 |
| Tonguea Endl., 1841 |
| Tricholobos Turcz., 1854 |
| Trochiscus O.E. Schulz, 1933 |