Ceratotheca sesamoides, locally known as mlenda mbata, is a wild leafy vegetable belonging to the Pedaliaceae family, native to Africa and commonly found in the central regions of Tanzania. It grows on sandy soils and at a range altitude of 800 – 1600m above sea level, spreading mostly in disturbed areas such as old pastoralist settlements and pastures where livestock usually graze. It’s a small, hairy annual herb, with green leaves and pink or lilac flowers, growing up to 1 m tall. Growth can be erect, but the stems are more commonly prostrate. The leaves are green, variable in shape, and usually 8cm long by 4.5cm across. They are tip pointed, toothed or lobed at the base, hairy and glandular below, on a hairy stalk. The upper leaves are much narrower with only a few teeth. The collection of mlenda mbata leaves takes place during the rainy season, though it can be found in smaller amounts throughout the year in fertile zones with good soil moisture. The leaves are usually collected in large amounts, dried in the sun before or after being steamed and stored. They can be also pounded and stored as a powder. Dried leaves can last for the entire dry season, which can last for up to 6 months. Women are usually in charge of the collection and processing of this vegetable.
Leaves and flowers are eaten fresh or dried. Once collected, fresh mlenda is wilted in the sun and cooked alone, with fresh peas or other leafy vegetables. A paste made from groundnut is used to season this dish. People appreciate mlenda for its mucilaginous texture and they use it in soup or for the preparation of jelly sauces served along with ugali.
The sun-dried leaves are usually pounded into a powder with other dry vegetables such as okra (Abelmoschus esculentus), pumpkin leaves (Cucurbita spp.) and/or African nightshade (Solanum nigrum). The mixture is boiled into a thick paste, mixed with groundnut paste and eaten with starchy foods.
Traditionally, mlenda mbata played an important role in the local diet, especially during droughts and famine periods. Because it was easy to find, the plant covered a crucial role in the diet and the household economy of rural communities. Due to its short harvesting season and the possibility to dry and store the leaves for long periods, mlenda mbata could fetch higher prices compared to other greens. However, its trade is mostly limited to rural areas and the amount sold is low as most families gather this species for home consumption. Once visible both at the household level and in the markets, mlenda mbata has lost importance in the last decades, becoming one of the least common African leafy vegetables sold in the public markets of Tanzania. People stigmatize its consumption, considering it a “food for the poor”. Also in rural areas, people tend to replace mlenda mbata with cultivated vegetables such as cabbage, kale, and spinach. Losing the traditional knowledge tied to this species could affect the resilience capacity of rural dwellers and affect their food security.