| Zaadplanten | Kern angiospermen |
| Claden_1 | eudicots |
| Claden_2 | core eudicots |
| Claden_3 | superasterids |
| Claden_4 | asterids |
| Claden_5 | lamiids |
| Domein | Eukaryota Whittaker & Margulis |
| Supergroep | Archaeplastida (Plantae) Adl et al. |
| Rijk | Viridiplantae Cavalier-Smith |
| Subrijk | Streptobionta Kenrick & Crane |
| Superstam | Embryophyta Engler |
| Stam | Magnoliophyta Cronquist, Takht. & W. Zimm. ex Reveal |
| Orde | Gentianales Juss. ex Bercht. & J.Presl |
| Familie | Rubiaceae Juss. |
| Subfamilie | Rubioideae Verdcourt |
| Tak | Spermacoceae Cham. & Schltdl. ex DC. |
| Geslacht | Houstonia L. |
| Soort | longifolia Gaertn. |
| Variëteit | tenuifolia (Nutt.) Alph.Wood |
| Synoniem | Hedyotis purpurea var. tenuifolia (Nutt.) Fosberg |
Houstonia longifolia Gaertn. var. tenuifolia (Nutt.) Alph.Wood
