1	Ovary with 1 ovule; fruit an achene.		(2)
+	Ovary with several or many ovules; fruit a follicle, rarely a capsule or berry.		(17)
2 (1)	Inflorescence with an involucre.		(3)
+	Inflorescence without an involucre.		(6)
3 (2)	Involucre contiguous with flower, calyxlike		25 Hepatica
+	Involucre separate from flower.		(4)
4 (3)	Leaves pinnatisect, penninerved; pollen grains spinulose		26 Anemoclema
+	Leaves 1 to few times palmately or subpinnately divided, palmately nerved; pollen grains not spinulose.		(5)
5 (4)	Style strongly elongate and plumose in fruit		27 Pulsatilla
+	Style not as above		24 Anemone
6 (2)	Petals absent.		(7)
+	Petals present.		(10)
7 (6)	Sepals valvate in bud; style usually strongly elongate and plumose in fruit; cauline leaves opposite, rarely alternate		29 Clematis
+	Sepals imbricate in bud; style not as above; cauline leaves (if present) alternate.		(8)
8 (7)	Achene (1--)3-ribbed on each side; leaves compound, rarely simple		21 Thalictrum
+	Achene not ribbed; leaves simple.		(9)
9 (8)	Basal leaves several, palmately lobed or undivided, veins reticulately anastomosing; staminodes absent		28 Metanemone
+	Basal leaf 1, palmatisect, veins dichotomously branched, not anastomosing; staminodes present		31 Kingdonia
10 (6)	Vines woody; cauline leaves opposite; style strongly elongate and plumose in fruit		30 Naravelia
+	Herbs perennial or annual; cauline leaves (if present) alternate; style not as above.		(11)
11 (10)	Petals without nectaries		33 Adonis
+	Petals with nectaries.		(12)
12 (11)	Aggregate fruit terete, achene with a robust, rostrate, persistent style at apex and 2 tubercles near base		38 Ceratocephala
+	Aggregate fruit not terete, achene with neither robust, rostrate, persistent style at apex nor tubercles near base.		(13)
13 (12)	Basal leaves several times pinnatisect; ovule pendulous from ovary locule apex		32 Callianthemum
+	Basal leaves not pinnatisect; ovule attached to ovary locule base.		(14)
14 (13)	Achene ribbed on each side.		(15)
+	Achene not ribbed.		(16)
15 (14)	Stolons absent; petals 13--15; achene 1-ribbed on each side		36 Oxygraphis
+	Stolons present; petals 5--10; achene 2- or 3-ribbed on each side		37 Halerpestes
16 (14)	Petals yellow; achene smooth, rarely spinulose or tuberculate		34 Ranunculus
+	Petals white, rarely yellow; achene transversely rugose on each side		35 Batrachium
17 (1)	Flowers zygomorphic; inflorescences usually racemose; pedicels 2-bracteolate.		(18)
+	Flower actinomorphic; inflorescences monochasial or, if racemose, pedicels ebracteolate.		(20)
18 (17)	Upper sepal spurless; petals clawed		10 Aconitum
+	Upper sepal spurred; petals clawless.		(19)
19 (18)	Staminodes 2, each differentiated into claw and limb; petals free; carpels 3--5(--7)		11 Delphinium
+	Staminodes absent; petals connate; carpel 1		12 Consolida
20 (17)	Flowers many, borne in compound cymes, panicles, or racemes.		(21)
+	Flowers solitary, terminal, or few in monochasia.		(24)
21 (20)	Leaves simple, undivided; petals and staminodes absent		4 Beesia
+	Leaves 1 or more times ternately or subpinnately compound; petals or staminodes present.		(22)
22 (21)	Proximal cauline leaves sheathlike; sepals 8--11 mm; fruit slender stipitate		5 Souliea
+	Proximal cauline leaves not sheathlike; sepals less than 4.5 mm; fruit shortly stipitate or sessile.		(23)
23 (22)	Fruit a berry; basal leaves scalelike		7 Actaea
+	Fruit a follicle; basal leaves not scalelike		6 Cimicifuga
24 (20)	Petals absent.		(25)
+	Petals present.		(27)
25 (24)	Leaves 2-ternate		14 Enemion
+	Leaves simple.		(26)
26 (25)	Leaves entire		1 Caltha
+	Leaves 3-sect		2 Calathodes
27 (24)	Carpels connate at base		22 Dichocarpum
+	Carpels free.		(28)
28 (27)	Petals long clawed.		(29)
+	Petals very shortly clawed or clawless.		(30)
29 (28)	Leaves simple, peltate, entire or palmately lobed; carpels 5--8, free		13 Asteropyrum
+	Leaves usually pedately compound, rarely ternate, not peltate; carpels 2, connate at base.		(28)
30 (28)	Carpels slender stipitate		23 Coptis
+	Carpels sessile.		(31)
31 (30)	Staminodes present, membranous, linear-lanceolate.		(32)
+	Staminodes absent.		(34)
32 (31)	Sepals white; stamens 8--14; style 1/6--1/5 as long as ovary		20 Semiaquilegia
+	Sepals blue or purple; stamens numerous; style ca. 1/2 as long as to longer than ovary.		(33)
33 (32)	Leaves all basal, simple, 3-sect, or ternate; petals ca. 1/3 as long as sepals, not petaloid (instead specialized nectariferous organs); style ca. 2 × as long as ovary; follicles cubic-globose		18 Urophysa
+	Leaves both basal and cauline, 2 or more times ternate; petals subequaling sepals, petaloid; style ca. 1/2 as long as ovary; follicles narrowly cylindric		19 Aquilegia
34 (31)	Leaves simple.		(35)
+	Leaves compound.		(37)
35 (34)	Leaves all basal; inflorescence with an involucre		9 Eranthis
+	Leaves both basal and cauline; inflorescence without an involucre.		(36)
36 (35)	Leaves palmatipartite or palmatisect; petals linear		3 Trollius
+	Leaves pedatisect; petals tubular or cupular		8 Helleborus
37 (34)	Leaves all basal, persistent remnants of petioles forming a dense clump; flower solitary, terminal; petals clawless		17 Paraquilegia
+	Leaves both basal and cauline, petioles not forming a clump; flowers few, borne in a monochasium; petals very shortly clawed.		(38)
38 (37)	Herbs perennial; carpels 1--5		15 Isopyrum
+	Herbs annual; carpels 6--20		16 Leptopyrum