ABSTRACT
The large number of species and the complexity of the genus Indigofera have lead to difficult delimitation between species. In order to contribute towards the taxonomy of the genus, diagnostic characters of the seed coat of seven Brazilian species of Indigofera with the utilization of surface examination and histological techniques were explored. Seeds are small, mostly rhomboid but sometimes cuboid or cylindrical, light greenish to dark brownish, exo-testal, albuminous, with medium-sized, circular to ovate, conspicuously colored hilum. Seedcoat has micro to macroreticulate microsculpture, phenolic macrosclereids and osteosclereids. Although considerable differences among the seedcoat anatomy within species was not found, it was possible to identify the species with basis on the combination of characters from seed coat microsculpture, both shape and size of the hilum and seeds, as well as the number of layers of osteosclereids. It is concluded that anatomy is a useful tool to set taxonomical patters within Indigofera.
Key words:
Anatomy; seed coat microsculpture; scanning electron microscopy; taxonomy; testa; seed