They are approximately 12 cm long and 4 mm across, and are slightly indented between the seeds. Sicklepod infestations can produce up to 10,000 seeds per square metre. In the Northern Territory it is widespread in the Darwin and Gulf regions. Dense, vigorous mono-specific stands manage to smother out most pasture species. This weed has the ability to become a serious pest in both horticultural and grain crops.
Sicklepod produces a toxic agent that causes skeletal muscle damage in livestock.
The two species can be distinguished by the dark brown glands between the lower pairs of leaflets on every compound leaf. Sicklepod has only one gland on the lower leaf, whereas foetid senna has glands between the two lower pairs of leaflets. Coffee senna has pointed leaflets and upwardly curving seed pods that are square in cross section. Candle bush has compound leaves up to 60 cm long, with eight to fourteen pairs of leaflets. The seed pods angle upwards from the stems, are 15 to 25 cm long, about 1.8 cm wide, and have prominent wings running along the sides.