Flow cytometry with propidium iodide (P.I.) as the D.N.A. stain was used to estimate their homoploidy genome size (2C) of six Cymbopogon martinii species collected from different locations (Ecotypical conditions) in Karnataka, India. Chromosome number was investigated for C. martinii and calculated the monoploid genome size of 6 different ecotypes of Cymbopogon martinii species. We observed intra-spatial genome size in six ecotypes, with a difference in morphology. The genome size found was lowest in ecotype (1.41 ± 0.006pg). Different genome size (2C) was observed for ecotype 3 (3.06 ± 0.020pg). Among the six ecotypes/varieties, 2.38 fold variation in genome size was observed. The correlation of nuclear D.N.A. content and chromosome number of the studied six ecotypes of Cymbopogon martinii species revealed the emergence of the evolutionary history. This work's genome size estimation will provide critical information for breeding and sequencing of Cymbopogon martinii species genome.