This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
A considerable order of plants when limited to the Ruteae proper; but the Aurantieae and Zanthoxyleae are now usually associated with them. These plants are remarkable amongst the Thalamifloreae for the glandular cysts abounding in the leaves and flowers, which often contain pungent strongly-scented bitter juices. There are very few hardy members of this family; the majority are found in South Africa and Australia. Ruta graveolens, Common Rue, is a familiar member of this order.