Centaurium
Carlström, A. 1986: New taxa and notes from the SE Aegean area and SW Turkey. – Willdenowia 16: 73-78Meikle, R.D. 1985: Flora of Cyprus 2Zeltner, L. 1970: Recherches de biosystématique sur les genres Blackstonia Huds. et Centaurium Hill. – Bull. Soc. Neuchateloise Sci. Nat. 93: 5-164Zeltner, L. 1985: Etude cytotaxonomique et cytogéographique de Centaurium pulchellum (Swartz) Druce, sensu lato. – Bot. Helv. 95: 47-57Zeltner, L. 1991: Contribution à l'étude cytogéographique des genres Blackstonia Huds. et Centaurium Hill (Gentianaceae) en Turquie, à Rhodes et à Chypre. – Bull. Soc. Neuchateloise Sci. Nat. 114: 77-103 This key is to be understood as provisional and for testing purposes. Further studies are needed to clarify if morphology correlates with caryological differentiation. The key is based on descriptions in the cited publications.
| 1 | Corolla yellow; corolla tube 15-20 mm long; capsule 12-15 mm long |
| 1' | Corolla pink, rarely white; corolla tube 6-16 mm long; capsule 7-12 mm long |
| 2 | Corolla lobes longer than 5 mm |
| 2' | Corolla lobes shorter than 5 mm |
| 3 | Leaves commonly forming a persistent rosette; corolla lobes 8-12 mm long |
| 3' | Without rosette or leaves forming a loose pseudo-rosette generally withering before anthesis; corolla lobes 5-8.5 mm long |
| 4 | Corolla tube 6-11 mm long; corolla lobes 5-8 mm long; plants branched from near the base |
| 4' | Corolla tube 12-16 mm long; corolla lobes 7-8.5 mm long; plants branched in the upper half only |
| 5 | Plants often branched from near the base; inflorescence lax, open |
| 5' | Plants often branched in the upper half only; inflorescence repeatedly branched, fastigiate |
| 6 | Flowers 2-90; corolla lobes dark pink; corolla tube not constricted below the limb; often with pseudo-rosette |
| 6' | Flowers 20-180; corolla lobes pale pink; corolla tube constricted below the limb; forming no rosette |
