genera

Torres-Montufar, Alejandro, Sanchez-Bautista, Saray & Aguilar-Morales, María, 2022, A synthesis of the Chiococceae tribe (Cinchonoideae, Rubiaceae) in Mexico: morphology, diversity, and endemism, Phytotaxa 542 (1), pp. 35-52 : 43-44

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