1 Leaves entire, simple; style various.

  2 Styles 2, distinct to the summit of the ovary

    3 Flowers in axillary cymes; capsule subglobose; leaves 2-12 cm long

    3 Flowers solitary or paired in the leaf axils; capsule cylindrical; leaves 0.5-8 cm long

  2 Styles absent (the stigma sessile and terminal), single, or with 2 branches.

      4 Ovary slightly 2-4-lobed, or not at all lobed; style terminal or reduced to a sessile terminal stigma

      4 Ovary deeply 4-parted; style gynobasic.

        5 Mericarps with glochidiate prickles (like grappling hooks), these visible early in development.

          6 Mericarps spreading or divergent, attached to the gynobase on the upper third of the mericarp.

             7 Flowering stem leafless above the first branch; corolla blue or white; [non-weedy natives]; [subfamily Cynoglossoideae; tribe Cynoglosseae; subtribe Amsinckiinae]

             7 Flowering stem with leaves above the first inflorescence branch; corolla blue, pink, or reddish-purple; [weedy exotics]; [subfamily Cynoglossoideae; tribe Cynoglosseae; subtribe Cynoglossinae]

          6 Mericarps erect, attached to the gynobase near the middle of the mericarp; [subfamily Cynoglossoideae; tribe Rochelieae; subtribe Eritrichiinae].

               8 Fruiting pedicels deflexed; plant perennial or biennial

               8 Fruiting pedicels erect-ascending; plant annual

        5 Mericarps smooth, rugose, or pitted, lacking glochidiate prickles.

                 9 Corolla rotate, lacking a well-developed tube, blue; [subfamily Boraginoideae; tribe Boragineae; subtribe Boragininae]

                 9 Corolla with a well-developed tube at least 3 mm long, of various colors (including blue).

                   10 Corolla lobes distinctly unequal, pink to blue; [subfamily Boraginoideae].

                     11 Stamens equal in length, entirely included within the corolla tube; [tribe Boragineae; subtribe Boragininae]

                     11 Stamens unequal in length, the longer conspicuously exserted; [tribe Lithospermeae]

                   10 Corolla lobes equal, of various colors (including pink to blue); [subfamily Cynoglossoideae].

                       12 Plant a scrambling climber with retrorsely prickly-hispid stems; [subfamily Cynoglossoideae; tribe Asperugeae]

                       12 Plant not climbing.

                          13 Mericarps attached laterally to a pyramidal gynobase.

                            14 Corolla yellow, the tube 4-5 mm long; corolla throat lacking appendages; [subfamily Cynoglossoideae; tribe Cynoglosseae; subtribe Amsinckiinae]

                            14 Corolla white (with a yellow eye), or pink to blue, the tube 6-20 mm long; corolla throat with appendages.

                              15 Corolla pink to blue (rarely white), 18-25 mm long; leaves elliptic or ovate; [plant a native, of moist, nutrient-rich habitats, and sometimes grown as an ornamental] ;[subfamily Cynoglossoideae; tribe Asperugeae]

                              15 Corolla white with a yellow eye; leaves linear; [plant a rare exotic, of disturbed habitats]; [subfamily Cynoglossoideae; tribe Cynoglosseae; subtribe Amsinckiinae]

                          13 Mericarps attached basally to a flat or broadly convex gynobase.

                                16 Mericarps laterally compressed, with an evident raised margin; [subfamily Cynoglossoideae; tribe Myosotideae]

                                16 Mericarps neither laterally compressed nor with an evident thickened margin.

                                  17 Mericarps with a prominent, toothed, basal rim; [subfamily Boraginoideae; tribe Boragineae; subtribe Boragininae]

                                  17 Mericarps lacking a prominent, toothed, basal rim; [subfamily Boraginoideae; tribe Lithospermeae].

                                    18 Corolla whitish or bluish white; plant annual from a slender taproot; leaves without evident lateral veins; mericarps brown, dull, wrinkled and pitted; [plant a weedy exotic]

                                    18 Corolla bright yellow-orange, or greenish-white; plant perennial from a thickened, woody rhizome; mericarps white, shining, smooth or pitted; [plant a native]

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. {add under 2b [Cynosciadium] APIACEAE}

    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 slightly bilaterally symmetrical (2 of the petals of different size than the other 3); fruit a capsular schizocarp of 5 mericarps; carpels 5

                                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 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

1 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

1 Inflorescence, flower, and fruit structure various, but not with the combination of features as above (sometimes the flowers in a head, e.g. Eryngium in APIACEAE, or the fruit a cypsela in Cevallia in LOASACEAE, but then with other features differing, such as stamens 4, or green calyx present, or fruit a schizocarp of mericarps, etc.).

  2 Perianth uniseriate, with only undifferentiated tepals; flowers many and small, greenish or brownish, inconspicuous individually; inflorescence of glomerules that are usually further aggregated into racemes or panicles; fruit an achene or utricle

  2 Perianth biseriate, both sepals and petals present and differentiated (except uniseriate and of 2 white to cream-colored sepals 5-10 mm long in Macleaya in PAPAVERACEAE); flowers larger, usually with the petals prominently colored; inflorescence various, but not as above; fruit a capsule, silique/silicle, or a schizocarp of 2 mericarps.

    3 Corolla bilaterally symmetrical and the petals connate into a tube (or the corolla 2-lipped but the corolla lobes twisted so as to make the flower asymmetrical); stamens 4; fruit a 2-locular and loculicidal capsule opening by 2 valves

    3 Corolla radially symmetrical and either connate into a tube or distinct (except Reseda in RESEDACEAE, with bilateral symmetry but separate petals); stamens 5 or more; fruit a silique/silicle, a schizocarp of 4 mericarps, or a 1-, 3-, or 4-locular capsule (2-locular in Ipomoea in CONVOLVULACEAE and Glaucium in PAPAVERACEAE), opening variously.

      4 Ovary inferior; fruit either a schizocarp of 2 mericarps (Eryngium), a 4-loculicidal (Oenothera) or apically dehiscent (Mentzelia) capsule with a persistent perianth (Mentzelia), or a cypsela (Cevallia).

        5 Flowers 4-merous, in a diffuse inflorescence; fruit a 4-locular capsule

        5 Flowers 5-merous (sometimes superficially 10+ in Mentzelia, the numerous "petals" actually a combination of 5+ petaloid stamen filaments and 5 petals).

          6 Flowers aggregated into a head; fruit a schizocarp of 2 mericarps

          6 Flowers solitary or in dichasia (Mentzelia) or if headlike, then plants with abundant trichomes, flowers yellow and fruit a cypsela with a persistent perianth (Cevallia); [LOASACEAE]

             7 Stamens 5; fruits indehiscent (a cypsela with a persistent perianth), bearing one seed each; plants with four trichome types (knobbed, retrorse, dendritic, and stinging), these sometimes but not always all present on the same plant.

             7 Stamens numerous (8-50+), often strongly exerted; petals 5 (sometimes superficially appearing to have ca. 10+ due to the presence of 5+ petaloid stamen filaments and 5 petals), fruits dehiscent (capsules with apical dehiscence); plants with two types of trichomes (antrorse/smooth or retrorse)

      4 Ovary superior; fruit either a silique/silicle, or a 1-, 2-, or 3-locular capsule, or a berry.

               8 Sepals and petals of different numbers, the sepals 2-3, the petals 0, 4, or 6; stamens many

               8 Sepals and petals the same number, 4-8 each; stamens 5 or 6 (10-25 in Reseda in RESEDACEAE).

                 9 Corolla bilaterally symmetrical; stamens 10-25

                 9 Corolla radially symmetrical; stamens 5 or 6.

                   10 Petals 4, distinct; stamens 6; fruit a silique/silicle

                   10 Petals 5, connate into a tube; stamens 5; fruit either a capsule or a berry.

                     11 Plant a twining vine.

                       12 Corolla with a long tube, much longer than the lobes, scarlet, white, pink, or blue; leaves shallowly to deeply pinnately parted into 3-many lobes

                       12 Corolla with a short tube, the lobes longer than the tube, purplish; leaves with a single large terminal l lobe, and 2 small basal lobes (these almost separate as leaflets)

                     11 Plant an erect or sprawling herb.

                          13 Fruit either a capsule, 2- or-3 locular, or a berry; corolla scarlet, blue, white, yellow, greenish-yellow, or purple, the tube long (>10 mm long) and cylindrical, the corolla > 10 mm long or wide.

                            14 Stigmas 3; fruit a capsule with 3 valves; leaf lobes 0.5-5 mm wide, often themselves lobed, the sinuses very deep, often nearly to the leaf midvein

                            14 Stigmas 2; fruit either a capsule with 2 valves or a berry; leaf lobes > 5 mm wide, not lobed themselves, the sinuses shallow, often < 1/2 way to the midvein