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Weed forms of adzuki bean frequently occur in Japan. The wide spread of weed forms is due to adaptation to human-disturbed habitats, escapes of old cultivars , and natural establishment from derivatives of hybrids between cultivars and wild forms.  In contrast to wild forms, the weed forms of adzuki bean are used as a substitute for the cultivated form and consumed as sweet beans, especially if cultivated adzuki beans are attacked by pests. However, in cultivated gardens the weed form is recognized as contamination and lowers the seed quality of adzuki cultivars. 
The name adzuki is a transliteration of the native Japanese name. Japanese also has a Chinese loanword , shōzu ( 小豆 ) , which means "small bean", its counterpart "large bean" ( 大豆 , daizu ) being the soybean. It is common to write 小豆 in kanji but pronounce it as azuki listen ( help · info ) , an example of jukujikun .
In Korean , adzuki beans are called pat ( 팥 ) and it contrasts with kong ( 콩 , "bean"), rather than being considered a type of it. Kong ("beans") without qualifiers usually means soybeans.