1	Shrubs or trees; leaves and stems sericeous, not glandular		1 Pluchea sericea
+	Annuals, perennials, or subshrubs; leaves and stems not sericeous, usually glandular		(2)
2 (1)	Stems (winged by decurrent leaf bases)		2 Pluchea sagittalis
+	Stems (not winged, leaf bases sometimes clasping, not decurrent)		(3)
3 (2)	Leaves petiolate, blades mostly elliptic, lanceolate, oblanceolate, oblong-elliptic, oblong-ovate, or ovate (bases not clasping)		(4)
+	Leaves sessile, blades mostly elliptic, lanceolate, oblong, or ovate (bases clasping to subclasping)		(6)
4 (3)	Subshrubs, 100–400 cm; leaf margins entire or denticulate (teeth callous-tipped).		3 Pluchea carolinensis
+	Annuals or perennials, 50–200+ cm; leaf margins serrate		(5)
5 (4)	Involucres 4–6 × 3–4 mm; phyllaries usually cream, sometimes purplish, usually minutely sessile-glandular, sometimes glabrate (the outermost puberulent); stems usually closely arachose (hairs appressed); arrays of heads paniculiform (of rounded-convex corymbiform clusters terminating branches from distal nodes, arrays usually resulting from strongly ascending, bracteate branches, the central axis longest, first to flower, and, rarely, the only component of an array); leaves petiolate; inland, non-saline habitats		4 Pluchea camphorata
+	Involucres 5–6 × 4–8(–10) mm; phyllaries usually cream, sometimes purplish, minutely sessile-glandular (outer also puberulent, hairs multicellular, viscid), sometimes glabrate; stems not arachnose; arrays of heads corymbiform (flat-topped to rounded, often layered, sometimes incorporating relatively long, leafy, lateral branches, clusters of heads terminal on leafy branches, some lateral branches nearly equaling or surpassing central portion); leaves sessile or petiolate; primarily coastal salt marshes, also inland habitats west of Mississippi River		5 Pluchea odorata
6 (3)	Leaves mostly 8–20 × 3–7 cm; involucres cylindro-campanulate, 9–12 mm (mid phyllaries 2.5–3 mm wide); phyllaries and corollas creamy white.		9 Pluchea longifolia
+	Leaves mostly 3–10 × 1–3 cm; involucres turbinate-campanulate to cylindro-campanulate, 5–8 mm (mid phyllaries 1–1.5 mm wide); phyllaries and corollas yellowish or creamy white to lavender, pale pink, pinkish, purplish, or rosy		(7)
7 (6)	Stems and leaves (slightly succulent, shiny) glandular, otherwise mostly glabrous; involucres 5–6 × 4–5 mm; phyllaries and corollas pink to lavender or cream or pinkish to rosy		8 Pluchea yucatanensis
+	Stems and leaves at least puberulent or arachnose as well as glandular; involucres 4–10 × 5–12 mm; phyllaries and corollas rose-pink to purplish, rose-purple, greenish, cream, or creamy white to yellowish, or pale pink		(8)
8 (7)	Phyllaries and corollas usually creamy white, sometimes cream, greenish, rose-purple, purplish, pale pink, or yellowish; involucres 5–10 × 6–9(–12) mm (bases rounded to impressed); phyllaries thinly arachnose and sessile-glandular		6 Pluchea foetida
+	Phyllaries and corollas rose-pink to purplish; involucres 4–6 × 5–9 mm (bases obtuse to barely acute); phyllaries usually arachnose (sometimes also with viscid hairs)		7 Pluchea baccharis