Bay Bean, Mackenzie Bean

Canavalia maritima
Fabaceae


Description

Beach Bean is a leguminous, drought and salt tolerant vine adapted to growing under very dry and hot conditions. History says that it was an important food crop for Captain James Cook and his crew on their voyage around the world from 1768-1771. Vines are widely distributed on beaches and dunes in the tropics and subtropics, also western and northern Australia. They can reach lengths of 6 m. (20 ft), compact mass is 15-30 cm (6-12 in) high and the flat woody pods filled with seeds are 10.2-15 cm (4-6 in) long.

Uses

Beach Bean is cultivated as a green manure crop or as a forage crop for cattle. Its long taproot, its habit of rooting at each node and fast growth make it a good choice for eroding sandy soils. Its dark green leaves and year-round pink flowers, which are nectar sources for bees, make Beach Bean a useful landscape plant in ocean coastal environments. Young pods and seeds are cooked and eaten but mature seeds are toxic when uncooked.

Cultivation

  • Elevation: Upper limits not known
  • Rainfall: Extremely drought-tolerant, tolerates high humidity
  • Soil types: Any type of sandy, rocky soil that is well-drained, either acid or slightly alkaline.
  • Temperature Range: 
  • Day length sensitivity: Beach Bean requires a long growing season.

Harvesting and Seed Production

Seeds are carried on ocean currents. They germinate easily if the seed coat is punctured or nicked to allow water absorption and gas exchange. Cuttings root rapidly when a stem tip with at least two nodes is used. New growth can reach 1.2–1.5 m (4-5 ft) in 2-3 weeks. Beach beans will tolerate occasional frosts. Pods should be allowed to dry on the plant. They will split open when seeds are ready to be harvested.

Pests and Diseases

No serious pests or diseases.

Cooking and Nutrition

Young pods and seeds of this bean species are eaten but only after cooking. Young seeds can be cooked and mashed for porridge. Fresh immature seeds contain toxic substances and should not be eaten raw. The flowers are used as a flavoring. Mature seeds must be thoroughly cooked. They may be roasted and added to coffee beans when coffee is scarce.