This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Low annual glabrous erect simple or branched herbs, with alternate small entire sessile or short-petioled leaves, or the lower opposite, and minute solitary axillary flowers. Calyx 4-5-parted, persistent, the lobes longer than the corolla. Corolla 4-5-cleft, marcescent, the tube subglobose, the lobes entire, acute, spreading. Stamens 4-5, inserted on the throat of the corolla; filaments short, glabrous, distinct; anthers ovate or cordate, obtuse; stigma capitate. Ovules numerous, amphitropous. Capsule globose, circumscissile, many-seeded. Seeds minute, flat on the back. [Latin, diminutive of cento, a patch.]
Three species, of wide geographic distribution. In addition to the following typical one, another occurs in Florida.
Centunculus minimus L. Sp. Pl. 116. 1753.
Simple or branched, very slender, 1'-6' high. Leaves spatulate, obovate or oblong, short-petioled, obtuse or acutish, 2"-4" long, 1"-2" wide; flowers sessile or very nearly so in the axils, shorter than the leaves, mostly 4-parted, 1"-2" broad; calyx-lobes linear or linear-lanceolate, acuminate; corolla pink; capsule shorter than the calyx.