1	Leaves pinnatisect, with ultimate lobules filiform, linear-filiform, filiform-clavate, narrowly lanceolate, or linear-lanceolate, (5-)10+ × 0.5-1(-1.5) mm, apex acute		(2)
+	Leaves pinnatipartite or pinnatisect, with ultimate lobules pectinate, serrate, or smoothly obtusely lacerate, less than 5(-8) × 1.5(-2) mm, or lobules minute but then lobes 1-2 mm wide with obtuse apex		(9)
2 (1)	Herbs annual, biennial, or short-lived perennial; rootstock a simple taproot, sometimes ± fusiform		(3)
+	Herbs perennial, subshrubs, or shrubs; rootstock often branched, ± woody		(6)
3 (2)	Herbs biennial or short-lived perennial; capitula obconical, 4-5 mm in diam.		52 A. fukudo
+	Herbs annual; capitula ovoid or subglobose, 2-3 mm in diam		(4)
4 (3)	Middle stem leaves pinnatisect, segments 2(or 3) pairs; plants pubescent, ± glabrescent.		53 A. przewalskii
+	Middle stem leaves 2- or 3-pinnatisect, segments (2 or)3 or 4 pairs; plants glabrous or nearly so		(5)
5 (4)	Stem branches short or absent; middle stem leaves (1 or)2-pinnatisect, segments (2 or)3 or 4 pairs; capitula 2-10 grouped, in narrow panicles.		46 A. palustris
+	Stem branches divaricate; middle stem leaves 2- or 3-pinnatisect, segments 4 or 5 pairs; capitula 2-5 grouped, in broad lax panicles.		47 A. aurata
6 (2)	Middle stem leaves 2- or 3-pinnatisect, lobules narrowly linear, densely silvery gray or yellowish sericeous-tomentose; corolla limb puberulent.		49 A. austriaca
+	Middle stem leaves 1- or 2-pinnatisect, lobules linear, filiform, or filiform-clavate, pubescent or arachnoid pubescent, sometimes glabrescent later, or densely white tomentose abaxially; corolla limb glabrous		(7)
7 (6)	Stem much branched; middle stem leaves 2-4 cm, 2(or 3)-pinnatisect; abaxial leaf surface and phyllaries densely white tomentose.		50 A. brachyloba
+	Stem shortly capitellate branched or not; middle stem leaves 0.8-2.5(-3) cm, 1- or 2-pinnatisect; leaves and phyllaries puberulent or leaves glabrescent		(8)
8 (7)	Stem terete; lobules of middle stem leaves filiform, apex acute.		44 A. adamsii
+	Stem 4-ribbed; lobules of middle stem leaves filiform-clavate or linear-filiform, apex obtuse.		45 A. dalai-lamae
9 (1)	Herbs annual or biennial; stem solitary, more than 20 cm; rootstock a simple taproot, sometimes ± fusiform		(10)
+	Herbs perennial or subshrubs; stems several or many, rarely solitary; roots usually woody, or herbs dwarf, less than 20 cm and with thick stock and ± fusiform root		(15)
10 (9)	Leaves ± succulent, middle stem leaves 1- or 2-pinnatisect, segments 1 or 2 pairs, with obtuse apex, entire or 1-3-crenate or cleft.		51 A. succulenta
+	Leaves thinly papery, middle stem leaves 2- or 3-pinnatisect, segments 2 or more pairs, lobes or lobules acute or obtuse apically		(11)
11 (10)	Basal leaves many, forming rosettes, segments more than 20 pairs; phyllaries with brown or purple-brown scarious margins; marginal female florets 3-8.		41 A. hedinii
+	Basal leaves not forming distinct rosettes, segments 3-8(-10) pairs; marginal female florets 10-12		(12)
12 (11)	Involucre 5-7 mm in diam.; phyllaries puberulent; disk florets 80-150; middle stem leaf segments 3 or 4 pairs, lobes serrate.		38 A. shangnanensis
+	Involucre 1.5-5(-7) mm in diam.; phyllaries glabrescent; disk florets 10-40; middle stem leaf segments 4-10 pairs, lobes pectinate		(13)
13 (12)	Lower stem leaf petioles 2-6 cm; leaf blades minutely and lanceolately pectinate; synflorescence narrow and spikelike.		42 A. tournefortiana
+	Lower stem leaf petioles less than 2 cm; leaf blades pectinate; synflorescence broader, often a conical, compound panicle		(14)
14 (13)	Middle stem leaves abaxially gray-yellowish or yellowish and gland-dotted; leaf rachis usually not pectinate, midvein obvious, slightly prominent; capitula 1.5-2.5 mm in diam.		40 A. annua
+	Middle stem leaves abaxially green, not gland-dotted; leaf rachis pectinate, midvein flat; capitula 3.5-5(-7) mm in diam.		39 A. caruifolia
15 (9)	Herbs dwarf perennial, main root ± fusiform; stem usually less than 15 cm tall; leaves 1(or 2)-palmatisect, segments 1 or 2 pairs, without lobules or occasionally with 2 or 3 minute lobules; synflorescence spikelike.		48 A. caespitosa
+	Herbs perennial or subshrubs, roots woody; stem more than 15 cm tall; leaves 1(or 2)-pinnatisect, segments 3 or more pairs; synflorescence paniculate, racemelike, or spikelike		(16)
16 (15)	Capitula broadly ovoid; phyllaries gray arachnoid pubescent; lobes of leaves suborbicularly and obtusely serrate.		31 A. baimaensis
+	Capitula hemispheric, globose, or subglobose; phyllaries puberulent, later glabrescent; lobes of leaves pectinate, or lobules lanceolate or linear-lanceolate, rarely linear-falcate		(17)
17 (16)	Middle stem leaves 1- or 2-pinnatipartite, lobules pectinate		(18)
+	Middle stem leaves 2- or 3(or 4)-pinnatisect, lobules serrate		(19)
18 (17)	Subshrubs; stem more than 70 cm; lobules of leaves elliptic or lanceolate and serrate; capitula 4-6 mm in diam.		32 A. medioxima
+	Herbs perennial; stem 20-70 cm; lobules of leaves pectinate; capitula 3-4 mm in diam.		35 A. latifolia
19 (17)	Capitula hemispheric, rarely subglobose, 4-7 mm in diam., in racemes, spikes, or panicles		(20)
+	Capitula subglobose, 2.5-4 mm in diam., in panicles		(25)
20 (19)	Herbs perennial; corolla limb puberulent		(21)
+	Subshrubs; corolla limb often glabrous		(22)
21 (20)	Middle stem leaves pinnatisect, segments 5-7(or 8) pairs, lobes pectinate or deeply serrate; phyllaries with entire broad brown scarious margins.		36 A. phaeolepis
+	Middle stem leaves 2-pinnatisect or -partite, segments 4(or 5) pairs, lateral mid-lobes deeply 2-4-serrate; phyllaries with lacerate brown scarious margins.		43 A. tsugitakaensis
22 (20)	Petioles of middle stem leaves 6-16 cm; leaves 1(or 2)-pinnatisect, lobes minutely irregularly pectinate-serrate.		34 A. maximovicziana
+	Petioles of middle stem leaves less than 3 cm; leaves 2 or 3(or 4)-pinnatisect, lobules minutely serrate		(23)
23 (22)	Middle stem leaves ± sessile, 2(or 3)-pinnatisect, lobules minutely linear or linear-lanceolate or falcate, 0.5(-1) mm wide; capitula sessile or shortly pedunculate; phyllaries pubescent.		24 A. macrantha
+	Middle stem leaves petiolate, 2 or 3(or 4)-pinnatisect, lobules minute, pectinate, linear, elliptic, or ovate, (0.5-)1-1.5 mm wide; capitula pedunculate; phyllaries glabrescent or puberulent		(24)
24 (23)	Middle stem leaves 3(or 4)-pinnatisect, segments 5-8 pairs, abaxial midvein obviously convex; peduncles 2-4 mm; phyllaries glabrescent.		26 A. polybotryoidea
+	Middle stem leaves 2(or 3)-pinnatisect, segments 3(or 4) pairs, abaxial midvein not convex; peduncles 4-15 mm; phyllaries puberulent.		27 A. aksaiensis
25 (19)	Middle stem leaves with 6-8 pairs of segments, abaxially white tomentulose.		37 A. tanacetifolia
+	Middle stem leaves with 3-5 pairs of segments, abaxially pubescent or glabrescent		(26)
26 (25)	Plants with short, woody vegetative shoots and slender, virgate synflorescences; petiole of middle stem leaves 0.3-0.5 cm; capitula with 16-20 disk florets.		33 A. freyniana
+	Plants much branched with most shoots fertile; petiole of middle stem leaves 0.8-5 cm; capitula usually with 20-60 disk florets (A. vestita with 12-20)		(27)
27 (26)	Leaf blade 0.3-0.7 × 0.2-0.5 cm.		11 A. obtusiloba (see A. sect. Absinthium)
+	Leaf blade 2-10 × 0.7-8 cm		(28)
28 (27)	Lobules of middle stem leaves entire, apex obtuse.		25 A. pontica
+	Lobules of middle stem leaves serrate or pectinate, apex acute		(29)
29 (28)	Middle stem leaves abaxially yellow arachnoid pubescent, lobules linear or narrowly lanceolate; capitula with 40-60 disk florets.		29 A. stechmanniana
+	Middle stem leaves abaxially gray pubescent, often glabrescent, lobules serrate or pectinate; capitula with 12-40 disk florets		(30)
30 (29)	Middle stem leaves triangular or elliptic-ovate in outline, lobules with triangular teeth; phyllaries puberulent or glabrescent; capitula with 20-40 disk florets.		28 A. gmelinii
+	Middle stem leaves ovate, elliptic-ovate, or suborbicular in outline, lobules deeply serrate; phyllaries densely pubescent; capitula with 12-20 disk florets.		30 A. vestita