Lupinus mutabilis Sweet

An erect annual herb. It grows to 1.5 m tall. It has a thick taproot. It can keep growing from year to year. The stems are branched, woody and mostly without hairs. The leaves have leaflets arranged like fingers on a hand. There are 7-9 leaflets. These are oblong and about 6 cm long by 1.4 cm wide. They are hairy underneath. The flowers are large and have a smell. They are about 2 cm long. The standard is white and blue with a yellow mark in the centre. Many flowers (50-70%) fall off without forming pods. The fruit is a pod. It is finely hairy and does not split open before falling in cultivated varieties. The pods are oblong but pointed at both ends. There can be 130 pods on a plant. The seeds bulge towards the centre. They are 8-10 mm long and 6-8 mm wide. The colour can vary from black to light grey.

A tropical plant. In Papua New Guinea it grows in high altitude regions at about 2,600 m. It has cold resistance. In the Andes they grow from 2,000 to 3,850 m altitude. It does not do well under high humidity and cannot tolerate drought at flowering. It requires 350-800 mm rainfall. It can grow in arid places.

The seeds are soaked overnight and the water discarded, then the beans cooked. CAUTION: The seeds contain poisonous alkaloids which are bitter, before soaking and washing. Varieties free of alkaloid are available. Up to 15% of lupin flour has been added to bread flour. The seeds are used in soups, stews and made into flour.

Plants are grown from seed. Rates of 100-120 kg per hectare are used. The seed is broadcast.