Senna plants are low-branching erect shrubs. Leaflets and pods are collected from cultivated plants of C. angustifolia and from both wild and cultivated plants of C. acutifolia. The branches are collected when the fruits are fully formed (but still unripe) and they are rapidly dried in the sun. Leaves are cleaned, sieved to remove leaf fragments and compressed into bales for transportation. Pods are hand picked into various qualities, finer ones being sold in cartons and the inferior ones used for making galenicals. Leaves and pods are important articles of commerce being used in the preparation of extracts, powders and for the isolation of active glycosides.

Indian senna is more carefully collected and has fewer broken leaflets than Alexandrian senna. P. ovata is a stemless annual herb from which seeds are collected from fully ripe fruits after drying. Seeds about 3 mm in length are covered with a mucilaginous husk on the concave side. They are very small weighing 1.5 g/1,000 seeds. This mucilaginous husk in the epidermis of the testa being the chief purgative constituent, it is separated from the seeds by crushing in flat stone grinding mills and winnowed to separate it. This forms the ‘Ispaghula husk’. Marketed as a separate commodity it fetches more price than the seeds.