1	Inflorescences flowering from base upward.		(2)
+	Inflorescences flowering from apex downward.		(3)
2 (1)	Leaflets of radical leaves usually truncate to subcordate at base; inflorescences usually nodding, thick; sepals white or pinkish; bracts longer than hypanthium in bud, densely hairy; filaments gradually dilated from base, broadest near middle, then gradually attenuate toward apex, narrower than anther, or sometimes little dilated.		6 S. alpina
+	Leaflets of radical leaves cordate or deeply so at base; inflorescences usually erect, long, slender; sepals white; bracts nearly equaling hypanthium in bud, abaxially sparsely hairy or subglabrous, margin ciliate; filaments compressed-dilated from middle to apex, broadest at apex, nearly as broad as anther.		7 S. stipulata
3 (1)	Inflorescences capitate; sepals white.		(4)
+	Inflorescences ellipsoid, cylindric, or elongate; sepals purple, red, pink or white.		(5)
4 (3)	Plants less than 35 cm tall; leaflets of radical leaves broadly ovate to suborbicular; flowers unisexual (females in center, males surrounding); style 0.5–1 × as long as sepals; fruiting hypanthium with 4 ribs.		4 S. filiformis
+	Plants to 85 cm tall; leaflets of radical leaves ovate, elliptic, or long elliptic; flowers bisexual; style equaling sepals; fruiting hypanthium with 4 winged ribs.		5 S. diandra
5 (3)	Filaments filiform, subequaling sepals.		1 S. officinalis
+	Filaments compressed-dilated, 0.5–2 × as long as sepals.		(6)
6 (5)	Leaflets of radical leaves linear-lanceolate, base subcordate or rounded to obliquely broadly cuneate, margin acutely incised serrate.		2 S. tenuifolia
+	Leaflets of radical leaves ovate, elliptical, or oblong, base cordate, margin coarsely obtusely serrate.		3 S. applanata