1	Stigmas 5 (rarely 4 in individual flowers); capsule with 5-10 teeth (rarely 4 or 8)		(2)
+	Stigmas 3 (rarely 4 or 5 in individual flowers, usually 4 in S. scaposa); capsules with 3 or 6 teeth (rarely 4, 5, 8, or 10)		(16)
2 (1)	Limbs of petals shorter than calyx, not differentiated from claw, ascending to spreading but rarely in horizontal plane; petals off-white, dingy pink, dusky purple, or purple tinged		(3)
+	Limbs of petals clearly differentiated from claw, spreading horizontally, equaling or longer than calyx (shorter in S. chalcedonica, S. flos-cuculi, and S. involucrata); petals showy, scarlet, bright purple or pink, or white		(9)
3 (2)	Seeds winged		(4)
+	Seeds not winged		(6)
4 (3)	Calyces inflated in flower or fruit, thin and papery; petals dusky purple-red; seeds 1.5-2.5 mm, with broad wing; flowers nodding (erect in subsp. porsildii but seeds 2-2.5 mm)		64 Silene uralensis
+	Calyces neither inflated nor very thin; petals white or pink; seeds 0.5-1.5 mm, wing often narrow; flowers erect		(5)
5 (4)	Seeds (0.5-)0.8-1(-1.3) mm, wing to ca. 4 diam. of seed; calyces elliptic, 7-10(-12) mm; stem 2-10(-12) cm; flowers 1(-3)		22 Silene hitchguirei
+	Seeds 1-1.5 mm, wing to 2 diam. of seed; calyces often campanulate or ovate, 8-20 mm; stems 10-45 cm; often with 1-3 flowers per peduncle		25 Silene involucrata (in part)
6 (3)	Fruiting calyces 2-3 times longer than broad, broadly tubular to narrowly ellipsoid		18 Silene drummondii
+	Fruiting calyces to 2 times as long as broad, campanulate, ovate, or elliptic		(7)
7 (6)	Fruiting calyces 10-12 mm, not or only slightly contracted at mouth		38 Silene ostenfeldii
+	Fruiting calyces 13-17 mm, contracted at mouth to 2-2/ 3 diam		(8)
8 (7)	Inflorescences 1(-3)-flowered; pedicels 2-3 times calyx, length of pubescence less than 1/ 2 pedicel diam.; veins of calyx prominent		26 Silene kingii
+	Inflorescences (1-)3-flowered; flowers sessile or pedicellate; pedicels usually much shorter than calyx, longest hairs ca. equaling pedicel or peduncle diam.; veins of calyx partially obscured by dense pubescence		57 Silene sorensenis
9 (2)	Inflorescences dense (interrupted in S. viscaria) cymes of (3-)5-50 flowers; flowers sessile or pedicels shorter than calyx		(10)
+	Inflorescences open cymes, 1-3 to many-flowered; most pedicels longer than calyx		(12)
10 (9)	Petals scarlet (rarely white or pink); coarse hispid herbs 50-100 cm; leaf blades broadly ovate or elliptic to lanceolate		9 Silene chalcedonica
+	Petals bright pink or purple (rarely white); glabrous or sparsely pubescent herbs 5-90 cm; leaf blades narrowly lanceolate		(11)
11 (10)	Flowers 14-22 mm diam.; limb of corolla obovate, ± entire; carpophore 3-5 mm; nodes of stem viscid		67 Silene viscaria
+	Flowers 5-10 mm diam.; limb of corolla 2-lobed to middle; carpophore ca. 1 mm; nodes of stem not viscid		61 Silene suecica
12 (9)	Open flowers 8-16 mm diam		25 Silene involucrata (in part)
+	Open flowers 20-35 mm diam		(13)
13 (12)	Petal limbs deeply divided with 4 linear segments		19 Silene flos-cuculi
+	Petal limbs unlobed, emarginate or shallowly 2-lobed		(14)
14 (13)	Leaf blades with dense, silky, grayish white tomentum; flowers bisexual		13 Silene coronaria
+	Pubescence hirsute or sparingly to densely pubescent; flowers unisexual		(15)
15 (14)	Petals white; capsule teeth slightly reflexed or spreading		28 Silene latifolia
+	Petals bright pink; capsule teeth revolute		16 Silene dioica
16 (1)	Petals scarlet		(17)
+	Petals white, cream, pink, or dark red, off-white tinged with purple		(23)
17 (16)	Limbs of petals unlobed or emarginate, shallowly dentate, or crenate, rarely shallowly 2-lobed		(18)
+	Limbs of petals deeply lobed or laciniate		(20)
18 (17)	Stems and leaf blades glabrous		60 Silene subciliata
+	Stems and leaf blades pubescent		(19)
19 (18)	Stems erect, 50-160 cm; inflorescences many-flowered; leaf blades ovate to lanceolate, apex acute, not acuminate		48 Silene regia
+	Stems ascending, 10-20 cm; inflorescences with flowers usually solitary, terminal; leaf blades linear-lanceolate, apex sharply acuminate		44 Silene plankii
20 (17)	Petals deeply 4-6-lobed, small lateral teeth may be present		27 Silene laciniata
+	Petals deeply 2-lobed, lobes often with lateral teeth		(21)
21 (20)	Leaf blades subrotund to broadly lanceolate; petal lobes ciliate		50 Silene rotundifolia
+	Leaf blades lanceolate, oblanceolate, or obovate to narrowly elliptic; petal lobes glabrous or nearly so (claw may be ciliate)		(22)
22 (21)	Stems 4-10(-15) cm; inflorescences 1-3(-4)-flowered; leaves longest in mid stem, basal tufts absent; w United States		55 Silene serpentinicola
+	Stems 20-80 cm; inflorescences (3-)7-11(-20)-flowered; leaves longest at base of stem, in basal tufts; e United States		66 Silene virginica
23 (16)	Calyces with 20-30 parallel veins		(24)
+	Calyces with 10 or fewer veins or venation obscure		(27)
24 (23)	Calyces glabrous, veins obscure		14 Silene csereii (in part)
+	Calyces pubescent and usually glandular, veins prominent		(25)
25 (24)	Mature calyces 20-30 mm; seeds 1.3-1.8 mm broad		12 Silene conoidea
+	Calyces 8-15 mm; seeds 0.6-1 mm broad		(26)
26 (25)	Petals ± equaling calyx, limb 1-3 mm, inconspicuous; corollas cream to dull orange abaxially, often purple tinged adaxially; calyx lobes 2-3 mm		11 Silene coniflora
+	Petals much exceeding calyx, conspicuous, limb 3-6 mm; corollas pink (rarely white or dark red); calyx lobes ca. 5 mm		10 Silene conica
27 (23)	Inflorescences congested, capitate, or flowers clustered; flowers sessile or pedicels shorter than calyx		(28)
+	Inflorescences open; flowers pedicellate, if pedicels short, then flowers in several separate whorls, or solitary		(30)
28 (27)	Plants glabrous		4 Silene armeria
+	Plants pubescent		(29)
29 (28)	Calyx veins purple tinged or entirely purple; corollas rose pink, limb 2-lobed		49 Silene repens (in part)
+	Calyx veins green; corollas greenish yellow to white, limb deeply lacin- iate into 6 or more linear lobes		40 Silene parishii (in part)
30 (27)	Leaves whorled at each node, 4 to many		(31)
+	Leaves opposite, 2 at each node (smaller axillary shoots sometimes present), or all or mostly proximal		(32)
31 (30)	Leaf blades lanceolate to ovate-lanceolate, 4 per node		59 Silene stellata
+	Leaf blades linear to very narrowly elliptic-lanceolate, more than 4 pernode		56 Silene sibirica
32 (30)	Calyces herbaceous, conspicuous pale commissures between veins absent, veins obscure		(33)
+	Calyces with pale commissures between prominent parallel veins		(43)
33 (32)	Limbs of petals with several narrow, linear lobes		7 Silene greenei
+	Limbs of petals unlobed, sometimes emarginate, or 2-lobed		(34)
34 (33)	Calyces glabrous		(35)
+	Calyces pubescent		(38)
35 (34)	Petals bright pink, rarely white		1 Silene acaulis
+	Petals white		(36)
36 (35)	Fruiting calyces ovoid, contracted at mouth to ca. 2 its diam.; stamens ca. 2 times calyx; filaments purple		14 Silene csereii (in part)
+	Fruiting calyces clavate or campanulate, not contracted at mouth; stamens ca. 1-11/ 3 times calyx; filaments usually white		(37)
37 (36)	Fruiting calyces broadly clavate, strongly contracted at base around carpophore; carpophores5-6 mm; inflorescences leafy		33 Silene nivea (in part)
+	Fruiting calyces campanulate, not contracted at base; carpophores 2-3 mm; inflorescences withleaves reduced, resembling bracts		68 Silene vulgaris
38 (34)	Seeds winged		58 Silene spaldingii
+	Seeds not winged		(39)
39 (38)	Mature calyces contracted towards base around carpophore; carpophores 4-7 mm		(40)
+	Mature calyces not contracted at base; carpophores less than 2 mm		(41)
40 (39)	Corollas white; calyces green		33 Silene nivea (in part)
+	Corollas pink (rarely white); calyces purple, purpleveined, or purple tinged		49 Silene repens (in part)
41 (39)	Leaf blades oblanceolate to elliptic-lanceolate, rarely obovate or elliptic, broadest distally or atmiddle		31 Silene menziesii
+	Leaf blades narrowly lanceolate to elliptic- or ovate-lanceolate, broadest proximally		(42)
42 (41)	Petals dark red (rarely white); calyces 6-9 ×3-4 mm		54 Silene seelyi
+	Petals white; calyces 9-11 × 4-6 mm		69 Silene williamsii
43 (32)	Plants annual or biennial, often with slender taproot		(44)
+	Plants perennial, rhizomatous or with stout, often woody taproot and branched (or sometimes in S. oregana), woody caudex		(49)
44 (43)	Mature calyces clavate, urceolate, or fusiform, contracted proximally around carpophore		(45)
+	Mature calyces campanulate, elliptic, or ovoid, not contracted at base around carpophore		(47)
45 (44)	Petals white, often pink tinged		34 Silene noctiflora
+	Petals bright pink		(46)
46 (45)	Petals unlobed		46 Silene pseudatocion
+	Petals 2-lobed		42 Silene pendula
47 (44)	Stems subglabrous to puberulent, often glutinous on distal internodes		2 Silene antirrhina
+	Stems coarsely hispid		(48)
48 (47)	Mature calyces (7-)10-15 mm; seeds grayish brown to black, ca. 1 mm    diam.; stems (20-)50-100 cm		15 Silene dichotoma
+	Mature calyces 7-10 mm; seeds dark reddish brown, ca. 0.5 mm diam.; stems 15-45 cm		20 Silene gallica
49 (43)	Calyx lobes equaling or exceeding tube		3 Silene aperta
+	Calyx lobes shorter than tube. [50. Shifted to left margin.—Ed.]		(50)
50 (49)	Mature calyces clavate, funnelform, turbinate, urceolate, tubular, or fusiform, narrowed proximally around carpophore		(51)
+	Mature calyces campanulate, elliptic, or ovate, not contracted proximally around carpophore, or if so, broadly turbinate or obconic, at least 1/ 2 as broad as long		(61)
51 (50)	Corolla limbs unlobed or nearly so		8 Silene caroliniana
+	Corolla limbs lobed or laciniate		(52)
52 (51)	Calyx lobes 4-8 mm, lanceolate or narrowly triangular		(53)
+	Calyx lobes 2-4 mm, lanceolate to ovate or triangular-acute, or 2-5 mm with broad, obtuse, membranous margins		(56)
53 (52)	Corollas coral pink, pink, or white, limb 7-25 mm; calyces umbilicate or turbinate in fruit		(54)
+	Corollas pale greenish yellow or pale yellow to white, sometimes purple tinged, limb 5-8 mm; calyces clavate in fruit		(55)
54 (53)	Corolla limbs laciniate into many narrow segments; calyces thinly pilose,funnelform in flower, umbilicate in fruit		45 Silene polypetala
+	Corolla limbs 4-lobed, usually deeply so, rarely 2-lobed with 2 smaller lateral teeth; calyces canescent, eglandular or glandular, broadly tubular inflower, turbinate in fruit		23 Silene hookeri
55 (53)	Corolla limbs deeply laciniate into 6 or more linear lobes; calyces (20-)25-30 mm, densely puberulent and viscid-glandular, tubular in flower		40 Silene parishii (in part)
+	Corolla limbs cleft ca. to middle into (2-)4-8 lanceolate to oblong lobes; calyces 16-20 mm, densely and coarsely pubescent and viscid-glandular,tubular to narrowly obconic in flower		70 Silene wrightii
56 (52)	Leaf blades ovate-acuminate, sessile; mature calyces turbinate		39 Silene ovata
+	Leaf blades linear or spatulate to ovate-lanceolate or oblanceolate, at least proximal ones petiolate; mature calyces clavate to tubular or fusiform		(57)
57 (56)	Corolla limbs pink or rose red (rarely white), (7-)10-20 mm, with 4 (rarely 2 with 2 teeth) divergent, lanceolate lobes; mature calyces 15-38 mm		36 Silene occidentalis
+	Corolla limbs white, greenish, pink, or dingy red, 3-8 mm, with 2-6(-10) linear lobes; mature calyces 8-17(-20) mm		(58)
58 (57)	Corolla limbs 2-lobed (rarely with small lateral teeth)		(59)
+	Corolla limbs 4-6-lobed		(60)
59 (58)	Inflorescences open cymes with many elongate, ascending branchesand pedicels longer than calyx		65 Silene verecunda
+	Inflorescences pseudoracemose and nodding with flowers usually paired at nodes and pedicels ± equaling calyx, or erect with dense, many-flowered whorls and most flowers sessile or shortlypedicellate		53 Silene scouleri (in part)
60 (58)	Corolla appendages 2, laciniate, apex rounded, 2-3 mm; claw andfilaments ciliate; corolla lobes 4, linear		5 Silene bernardina
+	Corolla appendages 4-6, linear, apex acute, 1-1.5 mm; claw and filaments glabrous; corolla lobes 4-6, often forked, producing to 10 linear segments		37 Silene oregana
61 (50)	Styles exceeding 2 times calyx; stamens exserted from calyx		(62)
+	Styles and stamens ± equaling calyx and/or corolla		(63)
62 (61)	Leaves mostly in dense basal tufts		29 Silene lemmonii
+	Leaves mostly cauline		6 Silene bridgesii
63 (61)	Sepals and pedicels without glandular hairs		(64)
+	Glandular hairs present at least on pedicels and calyces. [65. Shifted to left margin.—Ed.]		(65)
64 (63)	Petals to 2 times calyx		17 Silene douglasii (in part)
+	Petals slightly longer than calyx		32 Silene nachlingerae
65 (63)	Leaves mostly basal, densely tufted, cauline leaves usually in 1-3 pairs and/or reduced		(66)
+	Basal leaves not densely tufted; cauline leaves in 3-12 pairs		(72)
66 (65)	Corollas slightly longer than sepals, limbs 1-2 mm, unlobed, or apex notched		24 Silene invisa
+	Corollas exceeding or sometimes equaling calyces; limbs 2-10 mm, 2(-4)-lobed		(67)
67 (66)	Plants small alpine species; stems 3-20(-30) cm; leaf blades fleshy, 0.5-5(-6) cm		(68)
+	Plants lowland and montane species; stems usually exceeding 30 cm; leaf blades not fleshy, 2-15 cm		(70)
68 (67)	Pubescence on calyces and pedicels with purple septa		62 Silene suksdorfii
+	Pubescence on calyces and pedicels with colorless septa		(69)
69 (68)	Seeds 2-3 mm, margins thickened and winglike; proximal leaf blades oblanceolate-spatulate, 2-7 mm wide		21 Silene grayi
+	Seeds ca. 1.5 mm, margins with large inflated papillae; proximal leaf blades linear-oblanceolate, 0.5-3 mm wide		51 Silene sargentii
70 (67)	Calyx lobes narrowly lanceolate with narrow membranous margins proximally		35 Silene nuda
+	Calyx lobes ovate to broadly triangular with broad membranous margins		(71)
71 (70)	Claws of corollas exceeding calyx, ciliate proximally; veins to calyx lobes conspicuously broadened distally and lance-shaped, commissural veins slender, not forked distally		52 Silene scaposa
+	Claws of corollas equaling calyx, glabrous; veins of calyx lobes not conspicuously broadened distally, commissural veins slender and forked distally, connate with those to lobes		41 Silene parryi (in part)
72 (65)	Cymes sessile (proximal ones may be pedunculate); pedicels usually shorter than calyxand becoming deflexed at base of calyx		53 Silene scouleri (in part)
+	Cymes pedunculate or flowers solitary; pedicels shorter than to exceeding calyx, ascending (may be partially deflexed in S. thurberi and S. petersonii)		(73)
73 (72)	Petals bright pink, limb 5-15 mm; plants rhizomatous from thick rootstock; stems5-15 cm		43 Silene petersonii
+	Petals white, pale pink, or yellowish, often tinged green or dusky purple, limb 3-8 mm; plants not rhizomatous; stems erect, usually exceeding 15 cm		(74)
74 (73)	Pubescence on calyces and pedicels short, deflexed, grayish white, eglandular(glandular hairs often present in var. rupinae)		17 Silene douglasii (in part)
+	Pubescence scabrid-puberulent or often viscid glandular-pubescent with septate hairs, glandular hairs present at least distally		(75)
75 (74)	Mature calyces ca. as broad as long; flowers nocturnal		30 Silene marmorensis
+	Mature calyces ca. 2 times as long as broad, flowers diurnal		(76)
76 (75)	Corolla limbs 5-7 mm, mature calyces 12-16 mm; stems softly viscid-puberulent distally		41 Silene parryi (in part)
+	Corolla limbs 2-4 mm, mature calyces 7-12 mm; stems scabridpuberulent		(77)
77 (76)	Calyx lobes 1-2 mm, ovate, as long as broad, corolla appendagesentire		47 Silene rectiramea
+	Calyx lobes 3-4 mm, narrowly lanceolate, much longer than broad, corolla appendages erose		63 Silene thurberi