NYCTAGINACEAE

the four-o'clock family of flowering plants, in the pink order (Caryophyllales), containing about 30 genera with 300 species of herbs, shrubs, and trees, native to tropical and warm temperate areas of the world. Members of the family have smooth-edged leaves and petalless flowers; the flowers have coloured bracts (leaflike structures) that fuse together and resemble petals. The small dry fruit bears grooves or is winged. Four-o'clocks (Mirabilis jalapa), sand verbena (Abronia umbellata), and a showy vine of the South American genus Bougainvillea are widely cultivated as ornamentals. Small yellow Bougainvillea flowers have bright coloured bracts and hang from long, drooping branchlets. The stem of B. glabra may be 18 to 30 m (about 60 to 100 feet) long in warm climates, and the plant is in flower throughout most of the year. The stem of B. spectabilis is covered with many short hairs, and the flowers are relatively short-lived.