Herbs, annual or perennial. Stems unbranched or sparsely branched ; glandular-pubescent, glabrous, glabrescent, or scabrous. Leaves: stipules absent or scalelike; petiole with pulvinus basally or distally, (petiolule basally adnate, forming pulvinar disc); leaflets 1 or 3[-11] (flat). Inflorescences terminal or axillary (from distal leaves), racemes (flat-topped or elongated); bracts present [absent]. Flowers zygomorphic; sepals persistent, basally connate (1/2 of length), equal (each often subtending a nectary); petals equal; stamens  6; filaments inserted on a discoid or conical androgynophore, glabrous; anthers (oblong to linear), coiling as pollen is released; gynophore recurved in fruit [obsolete]. Fruits capsules, dehiscent, oblong. Seeds 4-25, reniform or ovoid-spheroidal, arillate or not, (cleft fused between ends). x = 10 (-).
Pet equal or nearly so, entire; receptacle bearing an adaxial, usually rounded or pointed, mostly greenish or yellowish gland between the cor and the androecium; style mostly (incl our spp.) very short; frs usually long-stipitate, reticulately veined, opening from the base upwards, the valves deciduous; annuals with palmately compound or trifoliolate lvs, simple bracts, and handsome fls in elongating terminal racemes. 200, mainly warm reg.
In addition to the following spp., the Middle-Eastern C. ornithopodioides L. is adventive on chrome ore piles in Ky. It is slender, to 5 dm, with strongly glandular stem, trifoliolate lvs (the lfls to 1.5 cm) and small fls (the pet only 1-2 mm) and frs (1.5-3.5 cm).
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.