1	"Fruit utricle (+- dehiscent in <i>Achyronychia</i>, <i>Scopulophila</i>); petals 0 or < 0.6 mm, scale-like; stamens on hypanthium rim; stipules present (except <i>Scleranthus</i>), scarious"	2
1	"Fruit capsule; petals generally present, > (0.6)1 mm, not scale-like; stamens on ovary base or disk surrounding ovary or ovary stalk; stipules generally 0"	7
2	"Stipules 0; hypanthium in fruit hard"	"Scleranthus {Scleranthus annuus subsp. annuus}"
2	"Stipules present; hypanthium in fruit +- hard or not (subfamily Paronychioideae)"	3
3	"Sepals widely ovate to reniform or round, margin scarious, awns 0; staminodes 14--19, thread-like, or 5, oblong, petal-like"	4
3	"Sepals lanceolate to oblong (if ovate or obovate, margin scarious, awns present, or margin not scarious, awns 0), margins scarious or not; staminodes 0 or 4--5, thread-like"	5
4	"Annual, base +- glabrous; stem prostrate to ascending; staminodes 14--19, +- 0.5 mm, thread-like, not petal-like; nectaries 0; style 2-branched"	"Achyronychia {Achyronychia cooperi}"
4	"Perennial herb, base densely woolly; stem erect; staminodes (pistillate flowers only) 5, 1--1.5 mm, oblong, petal-like; nectaries 5, wide; style 3-branched"	"Scopulophila {Scopulophila rixfordii}"
5	"Stipules 0.4--1 mm; sepal awn 0, hairs +- long, stiff, often hooked, margin green, not scarious"	Herniaria
5	"Stipules 1--8 mm; sepal awn 0.5--4 mm, hairs not as above, margin white, scarious, at least below"	6
6	"Sepal awn stout, spine-tipped, 1.5--4 mm; sepals densely woolly"	"Cardionema {Cardionema ramosissimum}"
6	"Sepal awn thread-like to +- stout, +- not spine-tipped, 0.5--1.5 mm; sepals not woolly"	Paronychia
7	"Sepals fused, tube prominent, lobes or teeth < tube (except <i>Agrostemma</i>); petal claw generally > limb, generally appendaged adaxially near limb base (subfamily Silenoideae)"	8
7	"Sepals +- free; petal claw < limb or generally 0, unappendaged"	16
8	"Styles 3--5; fruit valves or teeth 3--6 or 10"	9
8	"Styles 2; fruit valves or teeth generally 4"	11
9	"Calyx lobes > tube, generally 12--50 mm, linear, tube strongly 10-ribbed, with long, ascending, appressed hairs"	"Agrostemma {Agrostemma githago var. githago}"
9	"Calyx lobes or teeth < tube, < 13 mm, triangular to awl-like, tube not as above (except <i>Lychnis</i> with lobes 4--7 mm)"	10
10	"Styles (4)5, flowers bisexual; fruit teeth (4)5; plant densely silky-hairy to tomentose"	"Lychnis {Lychnis coronaria}"
10	"Styles 3(4,5), if 5 then flowers unisexual (taxa dioecious); fruit teeth 6, 10; plant glabrous or variously hairy but not as above"	Silene
11	"Flower or flowers subtended by 2--6 involucre bracts"	12
11	"Flower or flowers not subtended by involucre bracts"	13
12	"Calyx veins 20--45, tube not scarious between sepals; involucral bracts green, not scarious, linear to lanceolate, generally < 1 mm wide (ovate, 1.5--2.5 mm wide in <i>Dianthus deltoides</i>)"	Dianthus
12	"Calyx veins 15, tube scarious between sepals; involucral bracts red to brown, scarious, widely ovate, generally 5--12 mm wide"	Petrorhagia
13	"Stamens 5; calyx narrowly cylindric, 0.8--1 mm diam; flowers generally 1 in axils"	"Velezia {Velezia rigida}"
13	"Stamens 10; calyx cup-shaped to widely tubular, 1.5--9 mm diam; flowers few to many, in open to head-like, terminal cyme"	14
14	"Calyx tube +- 1.3--5 mm, cup- to bell-shaped, white-scarious between sepals"	Gypsophila
14	"Calyx tube 9--25 mm, ovoid to widely cylindric, green, not scarious between sepals"	15
15	"Perennial herb; inflorescence dense; pedicels generally 0--3 mm; calyx angles or keels 0; petal appendages 2"	"Saponaria {Saponaria officinalis}"
15	"Annual; inflorescence open; pedicels 5--40+ mm; calyx angles or keels 5; petal appendages 0"	"Vaccaria {Vaccaria hispanica}"
16	"Stipules 0.4--11 mm, widely triangular to bristle-like, scarious (subfamily Polycarpoideae)"	17
16	"Stipules 0 (subfamily Alsinoideae)"	20
17	"Leaf blade oblanceolate to obovate, petiole generally +- present; style 1, 3-branched, 0.1--0.3 mm (stipules not bristle-like)"	Polycarpon
17	"Leaf blade awl-like to linear, petiole 0; styles 3--5, free, generally 0.3--3 mm (if shorter, then stipules bristle-like)"	18
18	"Leaves opposite but appearing whorled due to axillary clusters of 16--30 per node; styles, fruit valves 5"	"Spergula {Spergula arvensis}"
18	"Leaves opposite, often with axillary clusters of < 16 per node but not appearing whorled; styles, fruit valves 3"	19
19	"Inflorescence axillary, flowers 1--2; sepals awned; petals 0 or vestigial; stipules bristle-like"	"Loeflingia {Loeflingia squarrosa}"
19	"Inflorescence terminal, flowers few to many; sepals not awned; petals present; stipules lanceolate to widely triangular"	Spergularia
20	"Petals +- 2-lobed, generally > 1/2 to base (petals sometimes 0 in <i>Stellaria</i>, <i>Cerastium</i>; lobes < 1/5 to base in <i>Pseudostellaria</i>)"	21
20	"Petals entire, irregularly toothed, or +- notched (sometimes 0 in <i>Minuartia</i>, <i>Moenchia</i>, <i>Sagina</i>)"	23
21	"Fruit cylindric, often +- curved in upper 1/2, opening by (8)10 teeth"	Cerastium
21	"Fruit spheric to +- ovoid, not curved in upper 1/2, opening by 6 (8 or 10) valves"	22
22	"Petals 2-lobed < 1/5 to base; fruit spheric, valves +- 2--3 &times; recoiled; seeds 1--2; rhizomes with tuber-like thickenings 3--12 mm diam or with +- vertical fleshy roots"	Pseudostellaria
22	"Petals 0 or 2-lobed > 1/2 to base; fruit +- ovoid or spheric to cylindric-oblong, valves ascending to recurved, not recoiled; seeds several to many; rhizomes with neither tuber-like thickenings nor vertical fleshy root"	Stellaria
23	"Petals +- irregularly toothed; inflorescence umbel-like; fruit opening by 6 teeth"	"Holosteum {Holosteum umbellatum subsp. umbellatum}"
23	"Petals 0 or entire or notched; inflorescence not umbel-like (except <i>Eremogone congesta</i>); fruit opening by 6 or 8 teeth or 3--6 valves"	24
24	"Fruit teeth 8; petals (0)4; plant erect; leaf blade +- linear, rigid, acute"	"Moenchia {Moenchia erecta subsp. erecta}"
24	"Fruit valves or teeth 3--6; petals 0 or 5 (if 4 then plant not erect, leaf blade not linear, not rigid, not acute)"	25
25	"Styles 4--5; fruit valves 4--5"	Sagina
25	"Styles 3; fruit valves 3 or 6 or teeth 6"	26
26	"Ovary sutures 3; fruit valves 3"	Minuartia
26	"Ovary sutures 6; fruit teeth or valves 6"	27
27	"Leaf blades needle-like to narrowly linear, often congested at or near base of flowering stems, tips generally sharp-pointed"	Eremogone
27	"Leaf blades ovate to lanceolate (narrowly so or not), not congested at or near base of flowering stems, tips generally acute to acuminate"	28
28	"Seed appendage 0; rhizome 0"	Arenaria
28	"Seed appendage +- 0.7 mm, +- elliptic, spongy; rhizome slender, branched"	"Moehringia {Moehringia macrophylla}"