Key to genera 1. Fruits drupaceous, indehiscent; seed apical attachment ....................................................................................................................2. - Fruits capsules, loculicidally or septicidally dehiscent; seed basal or medial attachment ................................................................3. 2. Ovary 2-locular; flower aestivation is valvate; corolla lobes deltoid; fruits flattended to subspheroidal........................... Chiococca - Ovary 5-10-locular; flower aestivation is imbricate; corolla lobes linear-lanceolate; fruits spheroidal ................................ Erithalis 3. Seed basal attachment............................................................................................................................................................ Lorencea - Seed medial attachment.....................................................................................................................................................................4. 4. Seeds wingless...................................................................................................................................................................................5. - Seeds winged.....................................................................................................................................................................................6. 5. Capsule dehiscent loculicidally; corolla tube 2 to 4 cm long; seeds 2 to 5 per locule ..................................................... Coutaportla - Capsule dehiscent septicidally; corolla tube 6 to 8 cm long; seeds numerous per locule...................................................... Nernstia 6. Flowers with linear corolla lobes ......................................................................................................................................................7. - Flowers with deltoid corolla lobes ................................................................................................................................................... 8. 7. Corolla tube 3 to 5 cm long; capsules flattened ................................................................................................................... Exostema - Corolla tube 1 to 2 cm long; capsules subcylindrical....................................................................................................... Solenandra. 8. Capsules flattened and septicidally dehiscent ....................................................................................................................... Coutarea - Capsules subcylindrical and loculicidally dehiscent ............................................................................................................. Hintonia

Published as part of Torres-Montufar, Alejandro, Sanchez-Bautista, Saray & Aguilar-Morales, María, 2022, A synthesis of the Chiococceae tribe (Cinchonoideae, Rubiaceae) in Mexico: morphology, diversity, and endemism, pp. 35-52 in Phytotaxa 542 (1) on pages 43-44, DOI: 10.11646/phytotaxa.542.1.3, http://zenodo.org/record/6404536