Lupines

Lupinus, commonly known as lupin, lupine, or regionally bluebonnet, is a genus of plants in the legume family Fabaceae. The genus includes over 199 species, with centres of diversity in North and South America. Smaller centres occur in North Africa and the Mediterranean. They are widely cultivated both as a food source and as ornamental plants, but are invasive to some areas. For instance, lupine has become an ecological problem in Iceland since the beginning of the 21st century.

The part of the plant which is eaten is the leguminous seed. It is nutritious, sustainable, and affordable. Because they are bitter and contain strong alkaloids, they must be pickled prior to consumption, to avoid toxicity. They can also be made into a flour and used as fertilizer. They were historically eaten in the Mediterranean, North Africa, and Latin America, but have now gained popularity in other parts of the world, such as Denmark and Belarus. In spite of lupins not being native to Australia, in the past decade it has produced 85 percent of commercially grown lupins.

There are ancient texts which refer to the utilization of lupine seeds, such as the Mishnah, and the Roman writer Pliny the Elder. Evidence of their consumption have been found in Egyptian Pharonic tombs and in the Western Galilee, Israel, with the latter dating back to hunter and gatherer Natufian cave residents.

The species are mostly herbaceous perennial plants 0.3–1.5 metres (1–5 feet) tall, but some are annual plants and a few are shrubs up to 3 m (10 ft) tall. An exception is the chamis de monte (Lupinus jaimehintonianus) of Oaxaca in Mexico, which is a tree up to 8 m (26 ft) tall.

Lupins have soft green to grey-green leaves which may be coated in silvery hairs, often densely so. The leaf blades are usually palmately divided into five to 28 leaflets, or reduced to a single leaflet in a few species of the southeastern United States and eastern South America.

The flowers are produced in dense or open whorls on an erect spike, each flower 1–2 centimetres (3⁄8–3⁄4 inch) long. The pea-like flowers have an upper standard, or banner, two lateral wings, and two lower petals fused into a keel. The flower shape has inspired common names such as bluebonnets and quaker bonnets.

The fruit is a pod containing several seeds. The seeds contain alkaloids which lend them a bitter taste.

Extrafloral nectaries have been found on a species in Arizona.