This is a complex genus with some species, especially Packera paupercula, being highly variable. Collectors should include vegetative basal rosette leaves (or take notes about their shape).
1. Basal and lowermost stem leaves clearly pinnate, terminal segment about as wide as long or wider; annual or winter-annual.
1. Basal and lower stem leaves unlobed, or with 1–2 pairs of small lobes, terminal segment clearly longer than wide; plants perennial, often rhizomatous.
2. Blades of basal rosette leaves cordate or ± truncate (abruptly contracted to the petiole).
3. Blades of major basal rosette leaves strongly cordate; colonial from elongated, branching, horizontal rhizomes at surface of ground; rays present and golden yellow; widespread.
3. Blades of rosette leaves ± truncate or abruptly contracted to the petiole; elongate rhizomes absent; rays absent or present and medium yellow; northern Michigan.
4. Rays absent or less than 6.5 mm long; basal rosette leaf blades glabrous; asexual reproduction absent; Lake Superior region.
4. Rays present, 5–9 mm long; basal rosette leaf blades sparsely arachnoid pubescent; vigorous asexual reproduction by adventitious shoots forming on roots; Isle Royale only.
2. Blades of basal rosette leaves (except sometimes the smallest) ± obtuse or tapering at the base.
5. Larger basal leaf blades ± broadly obovate, tapering into a petiole narrowly winged to its base; phyllaries broadest above the middle, thence rather abruptly tapered to the apex; plant with slender stolons giving rise to a rosette of leaves.
5. Larger basal leaf blades ± lanceolate to oblanceolate or narrowly elliptic, the petioles not winged; phyllaries usually tapered gradually from the middle or below; plant habit variable.