1	Heads in spiciform-racemiform to spiciform-paniculiform arrays (heads ± sessile); ray laminae white, abaxially purple-veined		(2)
+	Heads in racemiform or paniculiform arrays or in glomerules; ray laminae white or yellow, abaxially purple-veined or not		(3)
2 (1)	Peduncular bracts not or barely surpassing phyllaries; calyculi 0; phyllaries 3–7 mm, apices usually shorter than bodies; cypsela widths 0.6–0.75 times lengths		1a Hemizonia congesta subsp. clevelandii
+	Peduncular bracts (and calyculi) often notably surpassing phyllaries; calyculi usually of 5–7, sometimes 0, bractlets; phyllaries 6–12 mm, apices usually longer than bodies; cypsela widths 0.5–0.6 times lengths		1b Hemizonia congesta subsp. calyculata
3 (1)	Leaves usually puberulent and eglandular throughout, rarely the distal villous and glandular; heads in paniculiform arrays; ray laminae white, not purple-veined		1c Hemizonia congesta subsp. tracyi
+	Leaves pubescent, sericeous, or villous, all or the distal glandular; heads in paniculiform arrays or in glomerules; ray laminae white or yellow, abaxially purple-veined		(4)
4 (3)	Leaves ± villous (the distal with hairs at margins often longer); some or all heads usually in glomerules, sometimes in corymbiform or paniculiform arrays; phyllaries 6–10 mm, apices usually longer than bodies; ray laminae white		1d Hemizonia congesta subsp. congesta
+	Leaves pubescent, villous, or sericeous (the distal with hairs at margins not notably longer); heads in paniculiform arrays; phyllaries 3–7(–8) mm, apices usually shorter than bodies; ray laminae white or yellow		(5)
5 (4)	Ray laminae white		1e Hemizonia congesta subsp. luzulifolia
+	Ray laminae yellow		1f Hemizonia congesta subsp. lutescens