The genusMurdanniaRoyle (Commelinaceae) represents 21 authorised speciesin South India. The distribution and ecology of thegenus in South India has beenanalysed. The analysis showed that the habitat preference as laterite substrate (43%),grassland (29%), marshes (14%) and rocky substratum(9% each) and streamsides (5%).The altitudinal preference indicates that 38% ofMurdanniaspecies found in 700 1000m MSL, 28% in 1-70 m MSL, 19% in 40 700 m MSL and5% each in 1000 1200 mMSL, 1 1000 m MSL and 70 1000 m MSL. The population density of the speciesindicates that 62%Murdanniaspecies belongs to rare category, 24% belongs to commoncategory and 14% belongs to vulnerable category. Among this, 81% of species prefersexposed conditions and 19% prefers shade. It is concluded that the speciation anddiversification of the genusMurdanniain South India strongly correlates with altitudeand climatic conditions.