Common Name: FOUR O'CLOCK FAMILY
Habit: Annual, perennial herb, subshrub, [shrub, tree], glabrous or hairy. Stem: often forked. Leaf: opposite, sessile or petioled, pairs generally unequal; blade generally entire. Inflorescence: generally forked; spike, head-like cluster, or umbel, flowers rarely 1, bracts forming a calyx-like involucre or not. Flower: bisexual, generally +- radial (bilateral), sometimes cleistogamous in some genera; perianth of 1 whorl, generally petal-like, bell- to trumpet-shaped, base hardened, tightly surrounding ovary in fruit, lobes 3--5, generally notched to +- lobed; stamens 1--many; ovary superior (appearing inferior due to hardened perianth base), style 1. Fruit: achene in hardened perianth base; round to +- flat; smooth, angled, ribbed, or winged; glabrous, hairy, or glandular.
Genera In Family: 30 genera, 350 species: warm regions, especially America; some ornamental (Bougainvillea; Mirabilis, four o'clock).
eFlora Treatment Author: Andy Murdock, except as noted
Scientific Editor: Thomas J. Rosatti.

Common Name: RINGSTEM
Habit: Perennial herb from thick caudex. Stem: little-branched, erect, > 7 mm diam; internodes with sticky brown ring. Leaf: few, +- in lower 1/2, petioled; blade oblong to round, thick. Inflorescence: openly branched; flowers in head, raceme, or umbel-like cluster; bracts 1--3, free, not forming involucre. Flower: perianth funnel-shaped; stamens 3, exserted; stigma +- spheric, exserted. Fruit: inconspicuously 10-ribbed, glabrous.
Etymology: (Latin: ring stem, from sticky ring on internode) Note: Closely related to Boerhavia.
eFlora Treatment Author: Andy Murdock & Richard Spellenberg
Reference: Spellenberg 2003 FNANM 4:28--30