Phaseolus lunatus (Lima Bean, Sieva Been, Butter Bean)

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Eudicotyledons > Core Eudicots > Rosids > Eurosid I > Fabales > Family: Fabaceae > Subfamily: Papilionoideae

Lima Beans originate from Central and South America where they were domesticated at least 8500 years ago.

Wild Lima Beans originate from Central and South America where they are common in seasonally wet and dry climates. They grow as vines that grow over surrounding vegetation in the wet season and then die back in the dry season. They have perennial roots so the plant is able to grow back the following season. Domestication of P. lunatus appears to have taken place twice. The earlier domestication occurred in northwestern South America and produced the large Lima Bean varieties. The earliest evidence for this domestication comes from a Peruvian archaeological site (Guitarrero Cave) where Lima Bean seeds were found from levels dating to 6500 BC, 1000 years earlier than P. vulgaris beans found at the same site and earlier than maize domestication. Sieva Bean, Butter Bean and Baby Lima Bean varieties originate from the second domestication which occurred in Central America, probably in Guatemala although the earliest archaeological evidence is from Mexico dating to at the latest 800 AD. For both domestications, the earliest archaeological evidence comes from sites that are beyond the present day range of wild P. lunatus suggesting that domestication did not begin in the regions where these archaeological sites are situated. 

Growing of Lima Beans spread into North America from about 1300 AD. With European exploration, Lima Beans were brought back to Europe and were under cultivation there by the 1500's. 

Wild P. lunatus seeds have high levels of glucosides which break down to toxic hydrocyanic acid when the seeds are bruised or chewed. However, modern domesticated varieties, particularly those with white seeds, have minimal quantities and are not dangerous. Cooking in boiling water also destroys the cyanogens.

References

• Sauer, J.D. 1993. Historical geography of crop plants - a select roster. CRC Press, Boca Raton, Florida.

Text by Hamish G. Robertson