The lentil, Lens culinaris Medik, belongs to the Fabaceae/Leguminosae family, also known as Papilionaceae or pulses.
The annual lentil plant usually grows erect, 15 – 50 cm tall and carries branches from the bottom upwards. The leaves are alternate and paripinnate, with a simple tendril instead of the end-leaf. However, the plant either does not or seldom climb, despite the tendrils at the end of the leaves. The two-to-seven pairs of oblong-linear leaflets have a smooth margin and short petioles. There are also small stipules (3-7 mm) with white hairs.
The inflorescence consists of one to three papilionaceous flowers, typical for this family. The blueish-white corolla is relatively small, measuring only 5-6 mm and is bordered by the green calyx petals. The pointed teeth of the calyx petals are twice as long as the calyx tube. The main flowering period is in June. Lentils are mainly self-fertile, pollination by bees or bumble bees is rare. The pod formed after pollination is rhombic, flat, 8-15 mm long and 4-8 mm wide. It only contains one or two discus-shaped, flat, brownish-green to grey-brown, reddish or yellow, monochrome or finely mottled or speckled seeds.
Lentils are healthy and have a particularly high nutritional value thanks to their high levels of protein (ca. 25 %) and carbohydrates (ca. 60 %) and only small percentage of fat (ca. 2 %). Additionally, they have high levels of vitamins, fibre and minerals. The provitamin A contained in lentils is transformed by the body into vitamin A – important for our eyes and the immune system. Lentils are rich in B vitamins, which are important for stimulating and strengthening neural functions, and also in vitamin E, which protects cells. Moreover, they are rich in potassium, calcium, magnesium, phosphor, iron and zinc. Lentils are also very filling thanks to their high levels of carbohydrates.
Raw lentils contain indigestible, toxic ingredients, so-called lectins, which are neutralised by boiling or heating to a temperature of 75 °C.