It is an annual plant growing to 50 to 100 cm (2-3 feet) tall, with opposite leaves 4 to 14 cm (5.5 in) long with an entire margin; they are broad lanceolate, to 5 cm (2 in) broad, at the base of the plant, narrowing to just 1 cm (half an inch) broad on the flowering stem. The flowers are yellow to purple, tubular, 3 to 5 cm (1 to 2 in) long, with a four-lobed mouth.

Sesame is grown primarily for its oil-rich seeds, which come in a variety of colors, from cream-white to charcoal-black. In general, the paler varieties of sesame seem to be more valued in the West and Middle East, while the black varieties are prefered in China and Far East. The small sesame seed is used whole in cooking for its rich nutty flavour (although such heating damages their healthful polyunsaturated fats), and also yields sesame oil.