Fifty-one taxa were investigated to understand the variation in the gene sequence of the small subunit of Rubisco (rbcS). The nucleotide sequences of rbcS gene from GenBank were downloaded to generate a multiple sequence alignment using BioEdit. Later, a dendrogram was drawn from this alignment using Mesquite and the trees were searched using Nearest neighbour interchange and Subtree pruning & regrafting rearrangers. The resulting dendrograms resembled in topology with respect to the arrangement of a few taxa, while they differed with respect to the others. The present investigation reveals the considerable diversity in the nucleotide sequence of the rbcS gene among the taxa studied