1 Plant an annual (rarely a biennial) from a fibrous root system or a taproot; leaves with lateral lobes either broadly rounded (and toothed) apically and broadly triangular-cuneate or rounded at the base, or parallel-sided in their lower half and 3-5-lobed apically, the lateral lobes resembling the terminal lobe in shape and usually size; [of wet soil of swamps and wet fields]

  2 Leaves with lateral lobes broadly rounded (and toothed) apically and broadly triangular-cuneate or rounded at the base; plants fibrous-rooted; plants 1.5-10 dm tall, with 1 stem from the rosette; [widespread in our area]

  2 Leaves with lateral lobes parallel-sided in their lower half and 3-5-lobed apically; plants from a taproot; plants 2-6 dm tall, with 1-6 stems from the rosette; [LA and AR westward]

1 Plant a perennial (rarely a biennial) from a short caudex or longer rhizome; leaves with lateral lobes absent, or distinctly narrower than the terminal lobe; [of dry to mesic soils, but not generally as above].

    3 Principal leaves (especially the basal) pinnate-2-pinnatifid to 2-3-pinnatifid, the primary lateral segments mostly 0.5-5 mm wide.

      4 Primary leaf segments of basal leaves 2-5 mm wide; rachis winged, at least in the upper half of the leaf, with a narrow to broad wing 1-4 mm wide on either side, thus the leaf 2-pinnatifid

      4 Primary leaf segments of basal leaves 0.5-2 mm wide; rachis unwinged or with a very narrow wing < 1 mm wide on either side, thus the leaf 3-pinnate-pinnatifid (pinnate, the pinnae themselves 2-pinnate to 2-pinnatifid)

    3 Principal leaves entire, toothed, or irregularly and raggedly 1-pinnatifid.

        5 Basal leaves with leaf bases cordate, truncate, obliquely truncate, or rounded, abruptly tapering to the petiole; leaf blades either 0.8-2× as long as broad or 4-7× as long as broad.

          6 Leaf blades lanceolate, 4-7× as long as wide; [of high-elevation grass balds in the Blue Ridge of w. NC and e. TN]

          6 Leaf blades ovate, cordate, or reniform, 0.8-2× as long as wide; [not restricted to high-elevation grass balds].

             7 Leaves densely tomentose, 1-6.5 cm wide; [of serpentine barrens in w. NC]

        5 Basal leaves cuneate at the base, with leaf tissue often somewhat decurrent along upper petiole or petiole winged throughout; leaf blades oblong, elliptic, lanceolate, oblanceolate, or spathulate, 1.5-8× longer than broad.

               8 Plants glabrate to sparsely floccose when young, becoming glabrous to glabrate later in the growing season, though some species with some persistent floccose tomentum near the base or in the leaf axils (the leaves appearing green); basal leaves serrate or lobed.

                 9 Basal leaves ovate, orbicular, or reniform, the blade 0.8-2× as long as wide; plants often forming clonal patches by stolons or widely creeping rhizomes

                 9 Basal leaves oblanceolate, narrowly elliptic, the blade 2-8× as long as wide; plants usually not forming clonal patches by stolons or widely creeping rhizomes.

                   10 Heads many, generally 20-100; basal leaves (including petioles) up to 30 cm long and 3.5 cm wide

                   10 Heads few, generally 5-20; basal leaves (including petioles) up to 12 cm long and 2 cm wide.

                     11 Leaves with 11-25 teeth per margin; leaves not triple-nerved; plants 28-50 cm tall; larger basal leaves 10-26 cm long; stem leaves pinnatifid; [of wetlands: wet meadows, wet prairies, bogs, seeps, and wet pine savannas]

                     11 Leaves with 3-10 teeth per margin; leaves somewhat triple-nerved; plants 14-30 cm tall; larger basal leaves 5-10 cm long; stem leaves unlobed, entire or few-toothed; [of dry uplands: cobble bars, riverbanks, glades and barrens]

               8 Plants densely tomentose or floccose when young, remaining visibly tomentose throughout the growing season on the leaves (these appearing grayish because of the persistent tomentum); basal leaves entire, obscurely crenate, or serrate (rarely lobed).

                       12 Basal leaves (including petioles) mostly 10-25 cm long, held in a vertical posture; [Coastal Plain and Piedmont, rarely Mountains]

                       12 Basal leaves (including petioles) mostly 3-10 cm long, arching or prostrate; [Mountains].

                          13 Tomentum of leaf blades very fine and tight; [shale barrens and woodlands, w. VA and WV north to w. MD and wc. PA]

                          13 Tomentum of leaf blades coarser, looser; [calcareous, mafic, or ultramafic cliffs, barrens, and woodlands, w. VA and e. VA southward to w. NC and e. TN]

                            14 Basal leaves elliptic-oblong, broadest at the middle; stem leaves deeply pinnatisect to pinnatifid; leaf teeth sharp and usually doubly serrate; plants spreading by dark rhizomes 1-3 cm long and 1.5-2.0 mm in diameter; involucres 4.0-5.5 mm high, 5.5-7.5 mm wide

                            14 Basal leaves ovate-elliptic, broadest at or below middle; stem leaves pinnatifid in the proximal half and unlobed in the distal half; leaf teeth singly rounded-crenate; plants spreading by pale underground stolons 3-16 cm long and 0.9-1.5 mm in diameter; involucres 6-8 mm high, 9-11 mm wide