1 Leaves palmately cleft or compound; fertile stamens 10 (except in G. pusillum, and note that anthers are readily deciduous in all species)

1 Leaves either 3-foliolate or palmately 4-11-foliolate (all the leaflets attached at a common point, or the leaflets slightly pedate in Helleborus foetidus in RANUNCULACEAE).

  2 Inflorescence an involucrate head subtended by phyllaries, the heads solitary or many and variously arrayed in secondary inflorescences, the ovary inferior, the corolla connate and tubular at least basally, the calyx absent, the stamens 5, the fruit a cypsela

  2 Inflorescence, flower, and fruit structure various, but not with the combination of features as above.

    3 Leaflets obviously and sharply serrate; pistils 1 or 5-many; fruit an achene, or an aggregate of achenes, drupelets, or follicles.

      4 Leaflets 7-11, slightly pedate in their arrangement, evergreen

      4 Leaflets 3-9, palmate, deciduous

        5 Pistil 1; fruit an achene

        5 Pistils 5-many; fruit an aggregate of achenes, drupelets, or follicles

    3 Leaflets entire, finely denticulate, or very obscurely toothed (or irregularly serrate or lobed in Cardamine in BRASSICACEAE); pistil 1; fruit simple, a legume, capsule, silique, or berry.

          6 Corolla bilaterally symmetrical; petals 5; fruit a legume; carpel 1

          6 Corolla radially symmetrical; petals 4 or 5; fruit either an elongate capsule or a berry; carpels 1, 2, or 5.

             7 Leaflets radially arranged at the summit of the petiole, not differentiated in size or placement into a terminal leaflet and 2 lateral leaflets; leaflets prominently notched at the apex; petals 5, yellow; inflorescence axillary, cymose or umbelliform; carpels 5

             7 Leaflets differentiated in size and placement into a terminal leaflet and 2 or more lateral leaflets; leaflets not regularly notched at the apex (a few may be slightly retuse); petals 4, white, pink, or yellow; inflorescence terminal and racemose; carpels 1 or 2.

               8 Carpels 2; fruit a red berry; petals connate, purplish-blue

               8 Carpel 1; fruit a capsule; petals separate, white, pink, or yellow.

                 9 Stem leaves 1-3, alternate [or whorled or opposite]; leaflets 3, irregularly serrate, lacerate, or additionally divided or lobed; fruit a silique; carpels 2

                 9 Stem leaves >3, alternate; leaflets (1-) 3-7, each entire or obscurely toothed; fruit a capsule; carpel 1

1 Leaves either 1-pinnately compound (all leaflets attached to a central rachis) or more complexly compound (with several orders of branching, some leaflets at least attached to second-order branches from the rachis).

                   10 Inflorescence an involucrate head subtended by phyllaries, heads solitary or many, variously arrayed in secondary inflorescences; fruit a cypsela; ovary inferior

                   10 Inflorescence various, but not as above; fruit various, not as above; ovary superior.

                     11 Leaves 1-pinnately compound (all leaflets attached to a central rachis).

                       12 Flowers bilaterally symmetrical, papilionaceous; fruit a legume; leaves even-pinnately or odd-pinnately compound, the terminal leaflet sometimes replaced by a tendril; leaflets entire or at most minutely denticulate

                       12 Flowers radially symmetrical (or barely bilaterally symmetrical in Erodium in GERANIACEAE); fruit a capsule, capsular but of 5 mericarps, or an aggregate of achenes, nutlets, or follicles (in some cases the # of pistils from many down to 2 or even 1); leaves odd-pinnately compound, never with tendrils; leaflets serrate (or entire to shallowly lobed in Polemonium in POLEMONIACEAE, Cardamine in BRASSICACEAE, and Floerkea in LIMNANTHACEAE).

                          13 Pistils many (only 1-2 in Agrimonia, Poteridium, Poterium, and Sanguisorba); fruit an aggregate of achenes, nutlets, or follicles; hypanthium present; stamens 5-many (only 4 in Poteridium and Sanguisorba)

                          13 Pistil 1 (or deeply 2-3-lobed in Floerkea in LIMNANTHACEAE); fruit a silique, capsule, schizocarp of 2-3 mericarps, or a capsular schizocarp of 5 mericarps (Erodium in GERANIACEAE); hypanthium absent; stamens 3-6.

                            14 Petals 3

                            14 Petals 4-5.

                              15 Petals 4, distinct; stamens 6; inflorescence a terminal raceme; fruit a silique/silicle

                              15 Petals 5, fused (distinct in Erodium in GERANIACEAE); stamens 5; inflorescence axillary or terminal, cymose, consisting of subcapitate, umbel-like, or helicoid cymes; fruit either a capsule, or a capsular schizocarp of 5 mericarps (Erodium in GERANIACEAE).

                                16 Flowers radially symmetrical; fruit either a loculicidal capsule or a berry; carpels 2 or 3.

                                  17 Fruit a berry; fresh plant rankly fragrant

                                  17 Fruit a capsule; fresh plant not aromatic.

                                    18 Capsule 2-valvate; carpels 2; leaflets prominently serrate or with some tooth-like sublobes

                                    18 Capsule 3-valvate; carpels 3; leaflets with entire margins

                     11 Leaves more complexly compound (with 2 or more orders of branching, some leaflets at least attached to second-order branches from the rachis).

                                       19 Leaves 2× even-pinnate; flowers in spikes or spherical heads; fruit a legume or loment.

                                       19 Leaves either 2× odd-pinnate or more complexly 2-4× ternately or ternately-pinnately compound; flowers in various inflorescences; fruits various (not legumes or loments).

                                         20 Leaf segments linear, less than 2 mm wide.

                                           21 Inflorescence an umbel; ovary inferior, of 2 fused carpels; fruit a schizocarp of 2 mericarps

                                           21 Inflorescence either a terminal solitary flower or terminal raceme or panicle; ovary superior, either of 2 fused carpels or of 1-5or many distinct 1-carpellate pistils; fruit either a capsule or an aggregate of follicles or achenes.

                                             22 Ovary of 2 fused carpels; fruit a capsule (1-seeded and indehiscent in Fumaria)

                                             22 Ovary of 1-5or many distinct 1-carpellate pistils; fruit an aggregate of follicles or achenes

                                         20 Leaf segments broader, lanceolate, ovate, or elliptic, > 5 mm wide.

                                               23 Herbaceous vine climbing by axillary tendrils; stamens 8

                                               23 Erect or sprawling herb; stamens 5-6 or >15.

                                                 24 Leaflets sharply serrate, with usually many teeth on each leaflet side, the total number of “points” per leaflet > 10.

                                                    25 Inflorescence an umbel; ovary inferior, of 2 fused carpels; fruit a schizocarp of 2 mericarps; inflorescence an umbel

                                                    25 Inflorescence a panicle or raceme; ovary superior, of 1-8 carpels; fruit an aggregate of follicles, a single follicle, or an indehiscent berry-like fruit.

                                                      26 Flowers bisexual; carpels 1-8; fruit an aggregate of follicles, a single follicle, or an indehiscent berry-like fruit

                                                      26 Flowers unisexual; carpels (in pistillate flowers) of 3 (-5) carpels; fruit an aggregate of follicles

                                                 24 Leaflets entire, or with 1-several, broad, obtuse, rounded, or broadly acute “sublobes”, especially towards the tip of the leaflet, the total number of “points” per leaflet < 10.

                                                        27 Inflorescence an umbel; ovary inferior, of 2 fused carpels; fruit a schizocarp of 2 mericarps

                                                        27 Inflorescence a raceme, panicle, or cyme; ovary superior, of either 1-2 fused carpels or of many separate 1-carpellate pistils.

                                                          28 Perianth bilaterally symmetrical, the corolla of 4 fused petals; plant a scandent vine or erect or sprawling herb

                                                          28 Perianth radially symmetrical, of 1-5 whorls of separate perianth parts; plant an erect herb.

                                                            29 Perianth of 4-5 whorls of 3 parts each (some of the whorls modified into nectaries); pistil 1, 1-carpellate; fruit a drupelike, blue, naked seed; largest leaflets > 6 cm long, obviously longer than wide

                                                            29 Perianth of 1 whorl; of 4-5 parts; pistils many, each 1-carpellate; fruit an aggregate of achenes or an aggregate of follicles; largest leaflets either < 6 cm long, or if longer than 6 cm, also about as wide as long