Distribution: Found throughout the World - cosmopolitan - but centered in north-temperate areas. Texas with 13 genera and 55 species; and one, Abronia macrocarpa, listed as endangered. (Texas list)
Significant features: The leaves are simple, entire, estipulate, and usually opposite. The flowers are usually bisexual, have a 3-8-lobed uniseriate perianth of connate, petaloid sepals and are subtended by bracts that range in appearance from large and brightly colored to reduced and calyx-like. The androecium consists of 1 (usually = calyx lobes = 5)-30 hypogynous, commonly unequal stamens that may be either free or monadelphous. The gynoecium is a single simple pistil with a superior ovary containing one locule and one basal ovule. The fruit is an achene that is often enveloped by the persistent base of the androperianth, mostly calyx tube. Thus, the true fruit (mature ovary), which is often an achene, is enclosed by an outer layer that is often modified as a dispersal aid. This pome-like combination of perianth and gynoecium is known as an anthocarp.
jalapa - pink synsepalous calyx (left) subtended by green
bracts at anthesis. These reflex (right) at maturity to reveal
Bougainvillea sp. - flower with white synsepalous calyx subtended by pink bracts
More information on the Nyctaginaceae