any of various shrubs or small trees of the genus Ceanothus,native mostly to western North America and often cultivated for their ornamental foliage and showy clusters of usually blue or whitish flowers是什么意思_any of various shrubs or small trees of the genus Ceanothus,native mostly to western North America and often cultivated for their ornamental foliage and showy clusters of usually blue or whitish flowers在线翻译_英语_读音_用法_例句