The seeds vary from oblong to nearly round and have a papery seed coat that ranges in colour from whitish to dark purple. Peanut legumes have the peculiar habit of ripening underground, a phenomenon known as geocarpy.Seed length ranges from 7 to 21 mm and seed diameter from 5 to 13 mm. Seed weight is also an important distinguishing character, which ranges from 0.17 to 1.24 g. Colour of seed coat or testa is an important criteria for classifying cultivated groundnuts and this may also influence the marketability of a cultivar.