Transactions of seed coat of twelve species of Cassia L., namely C. alata L., C. angustifolia vahl., C. auriculata L., C. didymobotrya Fresen., C. glauca Lam., C. grandis Linn., C. hirsuta Linn., C. marylandica L., C. mimosoides DC., and C. pleuorocarpa F.Meull, C. siamea Lam., and C. spectabilis DC., were examined under scanning electron microscope. Variation in shape and size of the palisade and hourglass cells, occurrence of double layer of palisade cells in C. mimosoides, absence of endotestal hourglass cells in C. glauca, C. marylandica and C. mimosoides, appeared to be distinguishing characteristics for each species having taxonomic significance. The usefulness of these diagnostic characters of the testa depends on the levels of variation present among the different species of the same genus which may help in designing a key for identifying the taxa at specific level along with other characters of the seed.