Fig. 68. — Horehound (Marrubium vulgare). Photographed by E. R. Root.

HORSE-BEAN (Parkinsonia aculeata). — Retama. A graceful small tree or shrub, growing in warm regions and found from Florida to the Pacific Coast. The fragrant light yellow flowers open in spring, and after rain may appear at any time throughout the year. It is visited by bees but does not yield a surplus.