Zygophylleae
A natural order of shrubs or herbs, very rarely trees, principally inhabiting the hot and extra-tropical regions of both hemispheres. Flowers white, red, or yellow, rarely blue, hermaphrodite; sepals five, rarely four, generally imbricated; petals five or four, very rarely wanting, hypogynous, free, imbricated, or twisted, rarely valvate; disk convex or depressed, rarely annular, inconspicuous, or wanting; stamens usually double, or rarely treble or equal to, the number of petals, biseriate, the outer opposite the sepals; anthers versatile, longitudinally dehiscing; peduncles usually one or two, springing from the axils of the stipules, ebracteate or rarely bibracteolate, one-flowered. Fruit coriaceous or crustaceous, sometimes septicidal and dividing into two to ten cocci, sometimes a loculicidal capsule. Leaves opposite or alternate from the suppression of one, stipulate, bifoliolate or pinnate, rarely three-foliolate; leaflets entire, dotless, sometimes connate; stipules twin, persistent, sometimes spiny. The wood of Guaiacum is very hard, and heavier than water; it is employed by cabinet makers for the manufacture of objects exposed to weight or friction. The order embraces seventeen genera, and about 100 species. Examples: Chitonia, Guaiacum, Zygophyllum.