This plant can be weedy or invasive according to the authoritative sources noted below.This plant may be known by one or more common names in different places, and some are listed above. Click on an acronym to view each weed list, or click here for a composite list of
Weeds of the U.S.
Linnaeus, Sp. Pl. 2: 657. 1753;
(Linnaeus) P. Gaertner, B. Meyer & Scherbius;
(Linnaeus) de Candolle;
Annuals or, rarely, perennials;
(short-lived, terrestrial or of wet habitat, not submerged); usually glabrous, rarely hirsute, (trichomes cylindrical).
(often simple from base), erect, branched distally, (0.5-)1-10 (-14) dm, (sometimes hirsute proximally).
rosulate; blade [(4-)6-20(-30) cm × 10-50(-80) mm] margins lyrate-pinnatisect, (abaxial surface sometimes hirsute).
petiolate or subsessile; blade lyrate-pinnatisect, (lateral lobes oblong or ovate when present), (1.5-)2.5-10(-18) cm × (5-)8-25(-30) mm, (lateral lobes smaller than terminal), base auriculate or amplexicaul, margins subentire or irregularly dentate, sinuate, serrate, or crenate, (abaxial surface sometimes hirsute).
often considerably elongated.
divaricate or slightly to strongly reflexed, straight or curved, (2.5-)3-10(-14) mm.
sepals erect, oblong, 1.5-2.4(-2.6) × 0.5-1 mm; petals yellow or pale yellow, spatulate, (1.5-)1.8-2.5(-3) × 0.5-1.5(-2) mm; median filaments 1-2.5 mm; anthers ovate, 0.3-0.5 mm.
usually silicles, rarely siliques, often slightly curved, oblong, ellipsoid, or oblong-ovoid, (2.5-)4-10 × (1.5-)1.7-3(-3.5) mm; ovules 20-90 per ovary; style 0.2-1(-1.2) mm.
biseriate, brown to yellowish brown, ovoid or subglobose, 0.5-0.7(-0.9) mm (0.4- 0.6(-0.7) mm diam.), colliculate.
Subspecies 2 (2 in the flora): North America, Europe, Asia; introduced in n Mexico, South America, Australia.