zygophylleæ

Century Dictionary and Cyclopedia

1. n. An order of polypetalous plants, the bean-caper family, belonging to the series Discifioræ and the cohort Geraniales. It is characterized by flowers which usually bear a fleshy disk, five free glandless sepals, filaments augmented each by a small scale, and a furrowed angled or lobed ovary with two or more filiform ovules in each of the four or five cells. It incluldes about 110 species, classed in 18 genera, natives of tropical and warm climates, especially north of the equator. They are commonly shrubs or herbs with a woody base, bearing divaricate branches joiuted at their nodes. Their leaves are usually opposite and pinnate or composed of two entire leaflets; the twin persistent stipules are sometimes developed into spines. The flowers are white, red, or yellow, very rarely blue, usually solitary in the axils of the stipules. The principal genera are Zygophyllum (the type), Tribulus, Guaiacum, and Fagonia; 10 genera are monotypic; two species of Guaiacum (lignum-vitæ) become moderate trees. The woody species are remarkable for the extreme hardness of their wood, and several, as Guaiacum, produce a bitter and acrid bark. Their detersive foliage is used in the West Indies to scour floors. Some of the family are so abundant in the Egyptian desert as to constitute a characteristic feature of its vegetation.