Description:
Hermaphroditic, andromonoecious, or gynomonoecious, unarmed, typically pubescent (with glandular, multiseriate, stellate, dendritic trichomes), terrestrial, annual, biennial, or perennial herbs. Stems branched (rarely unbranched and scapose), leptocaulous. Leaves basal and/or cauline and alternate, petiolate, the bases sheathing and exstipulate; blades simple to ternately lobed or deeply dissected, the lobes linear to ovate or obovate, membranaceous to subcoriaceous, and toothed. Inflorescences terminal and axillary, erect, simple umbellate, often arranged in monochasial or dichasial cymes; bracts whorled at the base of the umbel and basally connate; pedicels long and slender, unarticulated. Calyx lobes 5 and inconspicuous or absent, petals 5, free, imbricate; stamens 5; carpels 2 (or functionally 1 through abortion), ovaries inferior, styles connate; the disc flattened or raised. Fruits dry schizocarps with entire or apically bifid (or rarely fully bifurcating) carpophores, glabrous to pubescent, smooth to papillate, rugose, or spiny, orbicular, semicircular, or elliptic, sometimes with dorsal ribs and/or wings, the base often cordate, transversely flattened laterally; endocarp sclerified. 2n = 22, 40, 44, 88.
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