1	Pappi usually of plumose or subplumose bristles (barbellate to subplumose, barbels mostly 0.5–1 mm, in L. acidota and L. ohlingerae)		(2)
+	Pappi usually of barbellate bristles (barbels mostly 0.1–0.4 mm)		(15)
2 (1)	Phyllary apices (at least inner) prolonged, ± spreading, ± dilated, petaloid (pink, purplish, white, or yellow)		10 Liatris elegans
+	Phyllary apices (at least of inner) acuminate, acute, cuspidate, mucronate, obtuse, rounded, rounded-acuminate, or truncate (seldom notably spreading, not dilated or petaloid)		(3)
3 (2)	Heads in cymiform or corymbiform to subcorymbiform arrays; peduncles (arcuate or ascending-spreading) 20–70 mm		(4)
+	Heads usually in racemiform to spiciform arrays, rarely borne singly; peduncles 0 or 1–10(–25) mm		(5)
4 (3)	Involucres cylindro-campanulate, 14–17 × 8–11 mm; phyllary apices usuallyrounded, often mucronate; Texas		7 Liatris cymosa
+	Involucres hemispheric to campanulate or broadly turbinate, 17–23 × 15–20 mm; phyllary apices usually rounded to obtuse (pappus bristles barbellate tosubplumose); Florida		30 Liatris ohlingerae (in part)
5 (3)	Leaves 3–5-nerved; florets 10–60; corollas (lobes adaxially hispid)		(6)
+	Leaves mostly 1-nerved, sometimes 3–5-nerved (L. acidota); florets (2–)3–6(–8) or 8–14(–16); corollas (lobes glabrous)		(9)
6 (5)	Phyllaries ± equal (outer usually as long as or longer than inner)		(7)
+	Phyllaries ± unequal (outer shorter)		(8)
7 (6)	Heads usually borne singly (each immediately subtended by relatively broad, foliaceous bracts longer than involucres); stems glabrous		1 Liatris compacta
+	Heads in racemiform to spiciform arrays; stems glabrous or puberulent-villous		2 Liatris squarrosa
8 (6)	Stems hirsute to piloso-hirsute; phyllary apices (at least inner) acute-acuminate (all usually spreading to reflexed on distal 1/5–1/3, usually without hyaline borders)		3 Liatris hirsuta
+	Stems usually glabrous; phyllary apices (at least inner) usually rounded, rounded-acuminate, or truncate, often stiffly mucronate (all essentially erect and appressed, usually with narrow hyaline borders)		4 Liatris cylindracea
9 (5)	Heads in loose, spiciform arrays (widely spaced, stems evident); florets 4–6(–8) or 8–14(–16)		(10)
+	Heads in dense, spiciform arrays (closely spaced, stems usually obscured); florets (2–)3–6(–8)		(11)
10 (9)	Florets 4–6(–8)		5 Liatris punctata (in part)
+	Florets 8–14(–16)		6 Liatris bracteata
11 (9)	Corms elongate or becoming rhizomes		5 Liatris punctata (in part)
+	Corms globose, subglobose, depressed-globose, or ovoid		(12)
12 (11)	Leaves 3(–5)-nerved (bases of basal often fibrous-persistent), cauline abruptly reduced distally (pappus bristles subplumose); coastal plain, Louisiana, Texas		16 Liatris acidota (in part)
+	Leaves 1-nerved (bases not fibrous-persistent), cauline usually gradually or little reduced, sometimes abruptly reduced, distally; inland habitats		(13)
13 (12)	Stems stipitate-glandular		9 Liatris glandulosa
+	Stems glabrous (not glandular)		(14)
14 (13)	Phyllaries (11–18) in (4–)5–6 series, mostly oblong-obovate, unequal (inner 7–9 mm), apices obtuse to truncate-rounded (each tipped by thick, often indurate apicula or mucros, lateral veins usually not evident beyond middle or at least on distal 1/3); flowering mostlymid–late Aug(–Oct)		5 Liatris punctata (in part)
+	Phyllaries (6–11) in 2–3 series, oblong-lanceolate to lanceolate-triangular, subequal (inner 11–12 mm), apices acute to acute-attenuate (sometimes with narrow tips, lateral veins usually evident beyond middle, continuingnearly to tips); flowering mid Jul–Aug(–Sep)		8 Liatris aestivalis
15 (1)	Heads borne singly or (2–30) in corymbiform to subcorymbiform arrays		(16)
+	Heads in racemiform to spiciform arrays		(17)
16 (15)	Involucres campanulate-turbinate, 10–19(–23) × (8–)10–17(–22) mm; phyllaries in ± 3–4 series, apices mostly long-acuminate (innermost short-acuminate); Alabama		12 Liatris oligocephala
+	Involucres hemispheric to campanulate or broadly turbinate, 17–23 × 15–20 mm; phyllaries in 6–7 series, apices rounded to obtuse; Florida		30 Liatris ohlingerae (in part)
17 (15)	Leaves 3- or 5-nerved		(18)
+	Leaves usually 1-nerved, sometimes 1- (or 3-) nerved		(22)
18 (17)	Stems glabrous (often sparsely sessile-glandular, leaf bases not fibrous-persistent); corolla tubes pilose inside		29 Liatris savannensis (in part)
+	Stems glabrous or piloso-puberulent (not glandular, leaf bases fibrous-persistent); corolla tubes glabrous inside		(19)
19 (18)	Phyllary apices obtuse to rounded		(20)
+	Phyllary apices acuminate, acute, or acute-acuminate		(21)
20 (19)	Basal leaves 6–12(–15) mm wide; Great Plains		13 Liatris lancifolia
+	Basal leaves (2–)4–10(–20) mm wide; e of Mississippi River		14 Liatris spicata
21 (19)	Phyllary apices acute to acute-acuminate (reflexed to curving-spreading,tips often ± dilated, nearly petaloid); florets (4–)5–8		15 Liatris pycnostachya
+	Phyllary apices acuminate to acute (erect and ± appressed); florets (2–)3–4(–5)		16 Liatris acidota (in part)
22 (17)	Phyllary apices (at least mid and inner) usually acuminate to acute or rounded to rounded-retuse and minutely involute-cuspidate to acuminate or apiculate		(23)
+	Phyllary apices (at least mid and inner) usually obtuse, rounded, or truncate, rarely acute (not rounded-retuse or cuspidate to apiculate)		(34)
23 (22)	Phyllaries narrowly triangular, margins without hyaline borders, apices (divergent), usually acuminate to acute; florets 10–12; w Louisiana, e Texas		11 Liatris tenuis
+	Phyllaries elliptic-oblong, lanceolate, oblong, oblong-lanceolate, oblong-obovate, obovate, ovate, ovate-triangular, or spatulate, margins usually with narrow hyaline borders, apices (erect) acuminate, acute, obtuse-angled, rounded, or rounded-retuse, sometimes minutely involute-cuspidate to apiculate; florets 3–6(–9) or 7–10(–12); mostly e of Mississippi River		(24)
24 (23)	Stems glabrous or sparsely pilose		(25)
+	Stems hirtellous (hairs spreading to slightly deflexed) or hirsute, piloso-puberulent, puberulent, strigoso-hirtellous, or strigoso-puberulent		(29)
25 (24)	Phyllary apices usually rounded-retuse and minutely involute-cuspidate to apiculate; corolla tubes glabrous inside		(26)
+	Phyllary apices acute, obtuse-angled, or rounded; corolla tubes pilose inside		(27)
26 (25)	Stems glabrous or sparsely pilose; basal (and proximal cauline) leaves linear (arising from separated nodes), 1–2(–2.5) mm wide, abruptly or gradually reduced distally, margins usually ciliate proximally, facesgland-dotted		17 Liatris tenuifolia
+	Stems glabrous; basal leaves (mostly arising from congested nodes) lance-linear to linear, (1–)2–6(–9) mm wide, abruptly reduced distally, margins not ciliate, faces (minutely white-dotted by stomates) weakly, if at all, gland-dotted		18 Liatris laevigata
27 (25)	Heads in racemiform to spiciform (often strongly secund) arrays; involucres (7–)11–15 mm; phyllaries oblong to oblong-oblanceolate;florets 3–6		21 Liatris pauciflora
+	Heads in racemiform to spiciform (sometimes secund) arrays; involucres (6–)7–9 mm; phyllaries ovate-triangular to oblong or oblong-lanceolate; florets 4–10(–12)		(28)
28 (27)	Heads in loose arrays (not secund, internodes 6–20 mm); phyllary apices sharply acute to obtuse-angled, apiculate (apicula thickened, not markedly involute, laminae relatively thick, usually with glands in pits, without superficial glands); florets 7–10(–12); basal and proximal cauline leaves (2–)4–9(–12) mm wide (usuallyabruptly, sometimes gradually, reduced distally)		23 Liatris virgata
+	Heads in dense arrays (often secund, internodes 1–5 mm); phyllary apices rounded, acuminate to involute-cuspidate (laminae relatively thin, glands superficial at least proximally); florets 4–7(–9); basal and proximal cauline leaves 2–5 mm wide (abruptly or gradually reduced distally)		24 Liatris cokeri
29 (24)	Stems hirsute, puberulent, piloso-puberulent, or strigoso-puberulent		(30)
+	Stems hirtellous (hairs spreading to slightly deflexed)		(32)
30 (29)	Corms elongated into rhizomes (irregularly shaped, sometimes with thickened, fibrous roots); involucres 8–10 mm		22 Liatris garberi
+	Corms globose to elongate; involucres 4–6(–7) mm		(31)
31 (30)	Cauline leaves (proximal) usually lanceolate, linear, linear-oblanceolate, or oblanceolate, sometimes narrowly spatulate, 2–8(–10) mm wide (bracts subtending proximal heads to 2 mm wide, abruptly differentiated from distal cauline leaves); phyllary apices usually rounded or obtuse-truncate, rarely acute		32 Liatris gracilis (in part)
+	Cauline leaves (proximal) spatulate (petioles slender, blades elliptic to lance-elliptic), (8–)11–22(–27) mm wide (bracts subtending proximal heads 2+ mm wide, grading gradually from distal cauline leaves); phyllary apices usually acuminate to acute, rarely obtuse		33 Liatris gholsonii (in part)
32 (29)	Heads in relatively loose, racemiform to spiciform (often secund)arrays		21 Liatris pauciflora
+	Heads in dense, spiciform (cylindric) arrays		(33)
33 (32)	Heads (rigidly ascending, appressed to rachises and each other, overlapping); phyllary margins usually not ciliolate, apices (erect) acuminate to acute		19 Liatris chapmanii
+	Heads (spreading to ascending, not strongly overlapping); phyllary margins ciliolate, apices (slightly spreading) acuminate to acute		20 Liatris provincialis
34 (22)	Stems glabrous (sometimes sparsely sessile-glandular, rarely sparsely to moderately pilose in L. pilosa)		(35)
+	Stems hispidulo-puberulent, piloso-puberulent, puberulent, puberulent-villous, strigoso-hirtellous, or strigoso-puberulent		(39)
35 (34)	Involucres 5–7(–9) mm; florets 4–5(–6); corolla tubes glabrous inside (pappi: lengthsusually ± 1/2 corollas)		28 Liatris microcephala
+	Involucres 6–10 mm; florets (6–)7–13(–17); corolla tubes pilose or glabrous (L. ligulistylis) inside (pappi: lengths usually equaling corollas, shorter in some populations of L. helleri)		(36)
36 (35)	Stems glabrous (often sparsely sessile-glandular); involucres (8–)9–11(–12) mm diam.; phyllaries: hyaline borders erose to lacerate, (0.2–)0.4–1 mm wide;florets 9–17		29 Liatris savannensis (in part)
+	Stems glabrous or sparsely to moderately pilose (not glandular); involucres 5–8(–10) mm diam.; phyllaries: hyaline borders smooth or erose to lacerate, 0.2–0.4 mm wide; florets (6–)7–13(–17)		(37)
37 (36)	Plants 15–55 cm; leaves weakly, if at all, gland-dotted; pappi: lengths 1/3–2/3 or equaling corollas; montane		25 Liatris helleri
+	Plants 40–120 cm; leaves ± gland-dotted; pappi: lengths ± equaling corollas; coastal plain and piedmont		(38)
38 (37)	Stems glabrous or sparsely or moderately pilose; heads in loose to dense arrays (internodes 1–7 mm); peduncles 0 or 1–10(–80) mm; involucres(7–)8–10 mm; phyllaries in (3–)4–5(–6) series		26 Liatris pilosa
+	Stems glabrous; heads in loose arrays (internodes 2–14 mm); peduncles 0 or 2(–7) mm; involucres 6–8 mm; phyllaries in 3–4(–5) series		27 Liatris elegantula
39 (34)	Involucres 2.5–7 mm diam.; florets 3–12		(40)
+	Involucres (6–)8–15 mm diam. (L. squarrulosa) or 13–22(–25) mm diam.; florets 11–80.		(42)
40 (39)	Stems moderately to densely strigoso-hirtellous; peduncles (divergent, arcuate-ascending) 10–25(–30) mm; involucres 5–7 mm diam.; phyllary apices rounded to subtruncate; florets 7–12		31 Liatris patens
+	Stems piloso-puberulent, puberulent, or strigoso-puberulent; peduncles 0 or (usually ascending) 2–10(–12) mm; involucres 2.5–4(–5) mm diam.; phyllary apices rounded or obtuse to acuminate or acute; florets 3–6(–9)		(41)
41 (40)	Proximal cauline leaves usually linear to linear-oblanceolate or oblanceolate, sometimes narrowly spatulate, 2–8(–10) mm wide (proximal floral bracts to 2 mm wide, abruptly differentiated from distal cauline leaves); phyllaryapices usually rounded or obtuse-truncate, rarely acute		32 Liatris gracilis (in part)
+	Proximal cauline leaves spatulate (blades elliptic to lance-elliptic), (8–)11–22(–27) mm wide (proximal floral bracts 2+ mm wide, gradually differentiated from distal cauline leaves); phyllary apices usually acuminate to acute,rarely obtuse		33 Liatris gholsonii (in part)
42 (39)	Peduncles usually (5–)8–50 mm, rarely 0; phyllaries (usually erect, rarely spreading-reflexing); florets 30–80 (19–33 in L. scariosa var. scariosa); corolla tubes glabrous or pilose inside		(43)
+	Peduncles usually 0, sometimes 1–8+ (rarely to 30 in L. squarrulosa) mm; phyllaries (at least outer) usually reflexing, sometimes erect; florets 11–30; corolla tubes pilose inside		(44)
43 (42)	Phyllary margins: hyaline borders erose to lacerate or irregular; corolla tubes glabrousinside; Great Plains, e slope of Rocky Mountains in United States		34 Liatris ligulistylis
+	Phyllary margins: hyaline borders none or relatively smooth; corolla tubes pilose orglabrous inside; ne and nc United States, adjacent Canada		35 Liatris scariosa
44 (42)	Phyllaries glabrous (bullate, hyaline borders relatively broad, often erose to lacerate or irregular)		36 Liatris aspera
+	Phyllaries glabrous or puberulent to puberulent-hirtellous (not bullate, hyaline borders none or relatively narrow, smooth)		37 Liatris squarrulosa