Chakunda or Sickle senna (Senna tora, family: Caesalpiniaceae) is an annual erect herb with branches, attaining a height of 1-1.5 m. Stem is hairless, slender or angular. Though the upperside of the stem is smoothless and has linear marks and somewhat odorous. It is a common herb in Bangladesh, found beside road, in fallow land, cropfield and waterside area. Sometimes it is found standing in water also. It is also found in the countries of South and Southeast Asia.
Other names: Kalkasham, Teraj, Eraj, Eraich, Gol eski, Choto kolkashundey (Though Senna sophera is also called by the same name by folks of the country).
The leaves look a lot like Dadmordon (Senna alata) but much smaller in size. These are compound, leaflet 3 pairs at the end of long pinnae, last pair is larger than others. Leaflet is obovate, 2.5-5 cm long and 1.5-2.5 cm wide with soft hairs, petioled, opposite.
Flowers are yellow and borne in pair at leaf axil, 1.5 cm wide. Petals 5, sepals 5. Flowering occurs in May-July. Propagation of the plant is caused by seeds.
Fruit is a pod, 10-30 cm, tip pointed, Seeds are rectangular, shiny and brown in color.
The plant is useful in migraine, asthma, worm infection, insect bite and skin diseases. Seeds are used as the substitute of Coffee.