Canavalia ensiformis (L.) DC.

[Jack bean]

To Japanese version

<The situation in Japan and information from the NIAS genebank>

Jack bean is not popular in Japan. It is called "Tachi natamame". The young pod is processed into several kinds of pickles locally called "Fukujin-zuke", "Nuka-zuke" and "Miso-zuke" (Hoshikawa 1981). Jack bean is considered to have been introduced into Japan after sword bean (in the early years of the Edo era, 16th century), and the cultivation of jack bean in Japan is less than that of sword bean.

<Origin>

Jack bean has been found in archaeological sites in Mexico dating back to 3000 B.C. It is considered to have been domesticated in Central America (Purseglove, 1974).

<Taxonomy>

Jack bean belongs to the subgenus Canavalia in the genus Canavalia. The genus Canavalia consists of 4 subgenera with 51 species (Smartt 1990). Westphal (1974) proposed that jack bean (C.ensiformis (L.) DC.) in the New World and oblique-seeded jack bean (C.plagiospermus Piper) should be treated as a single species together with sword bean (C.gladiata (Jacq.) DC.). 2n=22.

<Characteristics>

Jack bean is a perennial leguminous crop mainly cultivated in Central America and the Caribbian. Leaves are shiny. Seed is smaller than sword bean and reaches 2cm long. Seeds are white. Flower is pale purple.

<Uses>

Jack bean is usually grown as a green manure. It is also used as a fodder, but livestock eat it with reluctance. The young pods and immature seeds are used as vegetables (Purseglove, 1974).

<References>

Hoshikawa,K. 1981. Tachi natamame (Jack bean). in "Shokuyou Sakumotu" (Food Crops). Yoken-do, Tokyo. (in Japanese) pp.548-549.

Purseglove, J.W. 1974. Tropical Crops : Dicotyledons. London : Longman.pp.242-246.

Smartt,J. 1990. Grain Legumes. Cambridge University Press. pp.301-309.

Westphal, E. 1974. Pulses in Ethiopia, their taxonomy and ecological significance. Wageningen: Centre for Agricultural Publishing and Documentation (PUDOC). ( cited from Smartt,1990).