Black Sesame

Sesamum radiatum is native to West and Central Africa, where it grows both wild and in cultivation.

• Native range spans tropical regions of West Africa, including countries such as Nigeria, Ghana, Cameroon, and the Democratic Republic of the Congo
• Typically found in savanna zones and forest margins
• The genus Sesamum as a whole is believed to have originated in Africa, making the continent the center of diversity for sesame species
• Sesamum indicum (common sesame) was domesticated on the Indian subcontinent, but Sesamum radiatum has remained primarily an African crop with limited introduction to other tropical regions

Sesamum radiatum is an erect annual herb typically growing 60 to 150 cm tall, though height can vary with growing conditions.

Stem & Leaves:
• Stem is erect, branching, and covered with fine glandular hairs
• Leaves are variable in shape — lower leaves are often deeply 3-lobed to palmately compound, while upper leaves become progressively narrower and lanceolate
• Leaf margins may be serrated or entire depending on position
• Leaves are arranged alternately along the stem
• Leaf surfaces are softly pubescent (hairy)

Flowers:
• Flowers are solitary in leaf axils, borne on short pedicels
• Corolla is tubular, typically pink to purplish-pink, approximately 2–4 cm long
• Flowers are zygomorphic (bilaterally symmetrical), a characteristic feature of the order Lamiales
• Blooming occurs sequentially from lower to upper nodes

Fruit & Seeds:
• Fruit is an oblong capsule, approximately 2–3 cm long, with four locules (chambers)
• Capsule dehisces (splits open) longitudinally when mature to release seeds
• Seeds are small (~2–3 mm), flattened, oval, and dark brown to black in color
• Each capsule contains numerous seeds; a single plant can produce hundreds of seeds
• Seeds have a high oil content, comparable to common sesame

Sesamum radiatum thrives in tropical climates and is adapted to the environmental conditions of the West and Central African savanna and forest-savanna transition zones.

• Prefers warm temperatures typical of tropical lowlands
• Grows in areas with a distinct wet and dry season
• Commonly found at elevations from sea level to approximately 1,000 meters
• Tolerant of relatively poor soils but performs best in well-drained sandy loam
• Often cultivated as a rain-fed crop, relying on seasonal rainfall
• Flowers are pollinated by insects, particularly bees and other generalist pollinators attracted to the tubular, nectar-rich flowers
• Seeds are dispersed primarily by dehiscence of the capsule, which can eject seeds a short distance from the parent plant

Sesamum radiatum is cultivated on a small scale in parts of West and Central Africa, primarily as a subsistence or local market crop.

Climate & Light:
• Requires full sun for optimal growth and seed production
• Thrives in warm tropical temperatures; sensitive to frost
• Best suited to regions with a growing season of 90–120 days

Soil:
• Prefers well-drained sandy loam or loamy soils
• Tolerant of relatively low soil fertility
• Soil pH range of 5.5–7.5 is suitable

Watering:
• Moderate water requirements; drought-tolerant once established
• Excessive moisture or waterlogging can lead to root diseases
• Rain-fed cultivation is common; supplemental irrigation may improve yields in drier areas

Propagation:
• Propagated by seed, sown directly in the field after the onset of rains
• Seeds are typically broadcast or sown in rows at shallow depth (~1–2 cm)
• Germination occurs within 5–7 days under warm, moist conditions

Harvesting:
• Capsules are harvested when they begin to turn brown and show signs of splitting
• Plants are typically cut and dried before threshing to extract seeds
• Timing of harvest is critical — premature harvest reduces seed quality, while delayed harvest leads to seed loss from capsule dehiscence

Sesamum radiatum has multiple uses in food, traditional medicine, and agriculture across its native range.

Culinary Uses:
• Seeds are consumed raw, roasted, or ground into paste
• Used as a flavoring agent in soups, stews, and sauces in West African cuisine
• Seeds can be pressed for oil, which is used in cooking
• Young leaves are consumed as a leafy vegetable, often cooked in soups

Traditional Medicine:
• In various West African traditional medicine systems, the plant is used to treat ailments including fever, inflammation, and gastrointestinal complaints
• Leaves and seeds are prepared as decoctions or poultices
• Some preparations are used as galactagogues (to promote lactation)

Agricultural Uses:
• Sometimes grown as a companion or intercrop with other staple crops
• Potential as an underutilized crop for food security and crop diversification in tropical regions