The Encyclopedia Americana (1920)/Ruellia
RUELLIA (Neo Lat. named for Jean Ruel, a French botanist of the 16th century), a genus of herbs and shrubs of the family Scanthaceæ. The genus is characterized by opposite leaves, and bears flowers of large size in shades of violet, white and red, and occasionally yellow or orange. There are about 200 species, chiefly native to tropical America, while occasional varieties are found in Asia, Africa and Australia; and some eight varieties are found in the United States. About 20 varieties are under cultivation, some of them being especially desirable for greenhouse use. R. tuberosa is the “manyroot,” also called “spirit-leaf” and “snapdragon”; R. paniculata is a trailing variety found in Mexico and Jamaica and has inch-long blue corollas; R. ciliosa is a charming hardy species of southern United States; R. indigotica furnishes by maceration an indigo-like dye and is native to India, Burma and China.