VERBENACEAE

the verbena, or vervain, family of plants in the order Lamiales, a worldwide but mainly tropical grouping of about 100 genera and more than 2,600 species, some of which are important for their flowers. Members of the family have opposite or whorled leaves that are usually undivided. The flowers are aggregated in spikes, clusters, or racemes and usually consist of a tube flaring into four or five almost equally cut lobes. The type genus, Verbena (q.v.), contains about 250 species, almost all of them native to the Western Hemisphere. Outstanding among the 30 Petrea species, all tropical American, is a woody evergreen vine called purple wreath, or sandpaper vine (P. volubilis). It bears long, hanging clusters of violet-blue pansylike flowers and has oval leaves so rough as to be likened to sandpaper. The 220 species of the genus Lippia bear clusters of white, rose, or purplish flowers. L. canescens of South America is a matting ground cover with oblong leaves and small heads of yellow-throated, lilac flowers. Caryopteris, with 15 East Asian species, is exemplified by blue spirea, or bluebeard (C. incana), an oval-leaved shrub up to 1.5 m tall with clusters of bright blue flowers in the autumn. Other tropical plants such as the Chinese hat plant (Holmskioldia sanguinea) and species of pigeon berry, or golden dewdrop (Duranta), beauty berry (Callicarpa), and glory-bower (Clerodendrum) are cultivated as ornamentals. The shrub lemon verbena (Aloysia triphylla) is notable for its fragrant oil. The family also includes teak (Tectona grandis), an important timber tree of Southeast Asia (see teak).