Senna tora aka Foetid Cassia

Senna tora belongs to the pea family, Fabaceae. Its common names include sickle senna and stinking cassia. Kew places its native range in Central America. Useful Tropical Plants gives a broader range in tropical America. It has spread to other parts of the tropics. Records also place it across southern and tropical Asia. These include India, southern China, Sri Lanka, and Southeast Asia. Some records may confuse it with other senna species.

The plant can grow as an annual or perennial. Its stems can turn woody as they age. Kew also records a low shrub form. Listed heights suggest about 3.3–4.9 feet [1–1.5 metres] in cultivation. Useful Tropical Plants reports an upper height of 6.6 feet [2 metres]. Plants For A Future gives flowering from May to June. The flowers have both male and female parts. Insects pollinate them, and the plant is self-fertile. The supplied sources give few species-level details about leaves or fruit.

This senna grows in tropical and subtropical climates. It prefers full sun, though it can tolerate some shade. A deep sandy loam offers the stated preferred soil. The soil should drain well and have moderate fertility. Plants For A Future also lists sand, loam, and clay as suitable. It accepts mildly acid, neutral, and mildly alkaline soil. Moist soil suits cultivation, despite records from both dry and wet thickets. Wild sites include waste ground, farmed land, and riverbank sands. Sources also record it on slopes in southern China. They provide no firm cold-hardiness rating.

People gather wild plants for food and traditional medicine. They also grow it for seed used in dye work. Young leaves serve as a cooked vegetable. Roasted seeds can serve in place of coffee. Plants For A Future gives it a low food-use rating. Traditional uses include leaf treatments for stomach and skin complaints. Seed uses include treatments for constipation and some eye complaints. These records describe use, rather than proof of medical benefit. The sources report no known hazards. That does not establish safety for every person or pet.

The seeds have a use as a mordant in dyeing. Plants For A Future also reports a source of tannin. That source leaves doubt about whether seeds or pods supply it. The plant can grow in cultivated beds. Weed reports differ between the two plant-use sources. Useful Tropical Plants lists weed potential and records it in farmed ground. Plants For A Future instead marks it as not weedy. The supplied evidence names no specific pests or diseases.