The "Inu-kori-yanagi" (Salix integra) belongs to Salicaceae (the Willow family). It is a small deciduous tree that is found throughout Japan, as well as in the Southern Kuril Islands, the Korean Peninsula, northern China, and the Russian Far East. This tree grows in sunny marshes or stream banks and it can reach 2-3 m in height. The leaves are elliptic, about 5 cm long and opposite with dull points. It is dioecious. The short catkins are borne from March to May before foliation. The seeds are covered with woolly hairs. Its Japanese name comes from its resemblance to "Korean willow" (Salix koriyanagi)-a willow species cultivated for use in making willow trunks-but it is of inferior quality. It is called "杞柳" (qi liu) in Chinese.
In Korean, it's called "gae-ki-beo-deul" (개키버들). This is a compound word consisting of "dog" (gae: 키버들) + "Korean basket willow" (ki-beo-deul: 키버들). "gae" (개) is a prefix used to indicate that something is different or slightly inferior. "ki-beo-deul" (키버들) refers to the "Korean basket willow" (Salix koriyanagi), a species native to the Korean Peninsula.