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.
Herbs or shrubs with dense whorls of showy flowers. Calyx tubular, truncate, or 5-toothed. Upper lip of the corolla arched; the lower one spreading, 3-cleft. Stamens 4, the filaments of the upper pair with an awl-shaped appendage at the base. A small genus from the Mediterranean region and temperate Asia. The origin of the generic name is obscure, but is said to come from , a flame, in consequence of the down of some species having been used for wicks.
1. Ph. fruticosa. Jerusalem Sage. - A handsome shrubby species with lanceolate-ovate or oblong crenate acute leaves clothed with a yellowish down. Flowers yellow, in large axillary whorls or verticillasters in the axils of the upper leaves. A native of the South of Europe, flowering in Summer.
2. Ph. Herba-venti. Wind Herb. - An herbaceous peren-nial from 1 to 2 feet high. Leaves thick, oblong-lanceolate, toothed and hairy. Flowers purple and violet; corolla villous outside; calyx-teeth rigid and sharp. Also a native of the South of Europe.
Ph. tuberosa has purple flowers in which the upper lip of the corolla is bordered with a slender white fringe. Ph. Rus-selliana is clothed with a white down and has large whorls of yellow flowers.