A new microphyllous Psychotria has been discovered from the southern mountainous area of the state Oaxaca, similar in general habit and short few flowered inflorescences, to P. graciliflora Benth. in Oerst. and P. minarum Standl. et Steyerm., but not belonging to the Heteropsychotria subgenus with its large entire stipules. The Chomelia crassifolia Borhidi described from Tabasco was also discovered and abundantly collected in Oaxaca by the experts of the SERBO. Based on these more complete specimens a new amplified and corrected description is given.