1 Leaves pinnately compound; fruit 3-5-seeded; [subfamily Adoxoideae; tribe Sambuceae]

1 Leaves evergreen.

  2 Plant a shrub, erect, not requiring support.

    3 Leaves with spiny margins; fruit a drupe; [uncommon horticultural escapes].

      4 Flowers 5-merous, the petals clawed; leaves usually small (ca. 2-3 mm long or less); [FL]

      4 Flowers 4-merous; petals not clawed; leaves larger (the longer leaves usually > 3 mm long); [NC northeastward]

    3 Leaves with crenate or serrate margins (the teeth not bearing small spines); fruits various; [widespread natives and non-natives]

        5 Leaves slightly to strongly fleshy; inflorescence a head; [maritime situations]

        5 Leaves not fleshy; inflorescence either a head or otherwise; [collectively widespread].

          6 Leaves > 8 cm long, typically spotted with yellow, coarsely toothed; fruit a red drupe; [commonly cultivated, rarely seeding down nearby]

          6 Leaves < 8 cm long, not yellow-spotted, serrulate; fruit a capsule or purplish drupe; [plants native or cultivated].

             7 Inflorescence a head; [s. FL]

             7 Inflorescence otherwise; [more widespread].

               8 Corolla tubular, campanulate, bilaterally symmetrical; fruit a 1-seeded achene (rarely produced)

               8 Corolla radially symmetrical, with 4-5 distinct petals; fruit a 2-10-seeded capsule or drupe.

                 9 Fruit a 4-5-locular capsule, with 2 seeds per locule (though often fewer by abortion)

                 9 Fruit a (2-) 3-locular, purplish-black drupe, with (2-) 3 single-seeded stones

  2 Plant a subshrub, creeping shrub, or liana.

                   10 Leaves spinose-serrate; [exotics, rarely naturalized]

                   10 Leaves serrate (not spinose), serrulate, or crenate; [exotics and natives, collectively widespread].

                     11 Leaves slightly to strongly fleshy; inflorescence a head; [maritime situations]

                     11 Leaves not fleshy; inflorescence otherwise; [collectively widespread].

                       12 Leaves on vigorous shoots with a few coarse rounded teeth towards the base (most leaves entire)

                       12 Leaves serrulate to serrate, the teeth uniformly around the margin or concentrated towards the tip; fruit dry, either indehiscent and 1-seeded or capsular and with several seeds.

                          13 Flowers 5-merous; petals fused; fruit indehiscent, 1-seeded; [montane, from e. TN, WV, and w. MD northwards in our area]

                          13 Flowers 4- or 5-merous; petals separate; fruit capsular, dehiscent, several-seeded; [collectively widespread in our area]

1 Leaves deciduous.

                            14 Leaves slightly to strongly fleshy; inflorescence a head, subtended by an involucre of phyllaries; [maritime situations]

                            14 Leaves not fleshy; inflorescence, flower, and fruit structure various, but not with the combination of features as above (sometimes the flowers in a head subtended by bracts, but then with other features differing, such as stamens 4, or green calyx present, or petals separate, or fruit a schizocarp of mericarps, etc.); [collectively widespread].

                              15 Lianas climbing by twining or by adventitious roots.

                                16 Stems with retrorse prickles; foliage scabrous

                                16 Stems not prickly; foliage smooth to variously hairy, but not scabrous.

                                  17 Leaves on vigorous shoots with a few coarse rounded teeth towards the base (most leaves entire), the larger leaves < 3 cm wide; lianas climbing by twining; fruit a fleshy berry; flowers 5-merous, with a fused, tubular corolla

                                  17 Leaves serrate, the teeth towards the leaf apex, the larger leaves > 4 cm wide; lianas climbing by adventitious roots; fruit a capsule; flowers 7-10-merous, with separate petals

                              15 Upright shrubs or trees, lacking any adaptations for climbing.

                                    18 Trees; leaves often a mix of alternate and opposite.

                                       19 Leaves harshly scabrous on the upper surface; fruit a multiple of achenes; leaf venation pinnate but irregular

                                       19 Leaves not scabrous; fruit a 2-4-seeded drupe; leaf venation neatly pinnate, the lateral veins nearly straight and parallel to one another

                                    18 Shrubs or trees; leaves strictly opposite (or often subopposite in RHAMNACEAE).

                                         20 Trees; leaves palmately-veined, with 5 or more veins from the base; [rarely naturalizing]

                                         20 Shrubs; leaves either triple-veined from near the base or pinnate-veined; [collectively widespread and common]

                                           21 Leaves strongly triple-veined from at or near the base of the blade, the 2 lateral veins arching towards the tip and rejoining the midvein or nearly so (becoming diffuse before rejoining); petals 4, white; stamens 15-90

                                           21 Leaves pinnate-veined; petals various, not both 4 and white (except sometimes in Hydrangea); stamens 1-15 (except 15-30 in Exochorda in ROSACEAE).

                                             22 Inflorescence head-like; flowers sympetalous and 4-lobed; fruit 2 seeded

                                             22 Inflorescence more diffuse, with internal axes and pedicels; flowers not BOTH sympetalous and 4-lobed (except in Forsythia and Buddleja, which have conspicuous axillary or paniculate inflorescences); fruit 1-seeded, 2-4-seeded, or 4-many-seeded.

                                               23 Plants in flower.

                                                 24 Corolla absent; flowers inconspicuous and small, in axillary fascicles or catkins.

                                                    25 Flowers in catkins; leaves usually a mix of opposite and alternate

                                                    25 Flowers in axillary fascicles; leaves strictly opposite (subopposite)

                                                 24 Corolla present; flowers larger, in terminal cymes, corymbs, racemes, panicles, or in axillary cymes or fascicles.

                                                      26 Petals separate; stamens 8-10 (-60) (or 4-6 in RHAMNACEAE and Euonymus in CELASTRACEAE).

                                                        27 Flowers 1-few, in axillary cymes; stamens 4-6; stems brown, tan, gray, or green.

                                                          28 Leaf venation pinnate, but irregular and reticulated; stems green

                                                          28 Leaf venation neatly pinnate, the lateral veins nearly straight and parallel to one another; stems brown, tan, or gray

                                                        27 Flowers 1 and terminal, or many, in terminal panicles or corymbs; stamens 8-10 (-60); stems brown, tan or gray.

                                                            29 Inflorescence a solitary, terminal flower; stamens 30-60

                                                            29 Inflorescence a terminal panicle or corymb; stamens 8-15

                                                      26 Petals fused, at least basally, and often strongly tubular; stamens 2, 4, or 5.

                                                              30 Stamens 5.

                                                                 31 Petals pink, yellow, or reddish, fused for most of their length

                                                              30 Stamens 2 or 4.

                                                                   32 Stamens 2; petals yellow; flowers radially symmetrical; inflorescence an axillary fascicle

                                                                   32 Stamens 4; petals white, pink, or lavender; flowers bilabiate; inflorescence a terminal thyrse or panicle or an axillary cyme.

                                                                     33 Petals 4; inflorescence a terminal thyrse

                                                                     33 Petals 5; inflorescence a terminal panicle or an axillary cyme.

                                                                       34 Inflorescence an axillary cyme

                                                                       34 Inflorescence a terminal panicle

                                                                         35 Flowers lavender; fruit a shiny orange drupe (appearing berry-like)

                                                                         35 Flowers pinkish-white; fruit a bristly achene

                                               23 Plants in fruit.

                                                                           36 Fruit a berry, drupe, or achene, indehiscent, fleshy at maturity (or dry in Kolkwitzia).

                                                                              37 Fruit a berry, with 20+ seeds

                                                                              37 Fruit a drupe or achene, with 1-4 seeds.

                                                                                38 Fruit an achene (1-seeded), dry at maturity

                                                                                38 Fruit a drupe (1-4-seeded), fleshy at maturity.

                                                                                  39 Inflorescence axillary, fascicled or a cyme.

                                                                                    40 Foliage with stellate hairs; fruit a pink-purple 4-seeded drupe

                                                                                    40 Foliage glabrous or with simple hairs; fruit a dark red, black, or blue 1-4-seeded drupe.

                                                                                      41 Fruit a 1-seeded drupe; [NC southwards and westwards]

                                                                                      41 Fruit a 2-4-seeded drupe; [widespread in our region]

                                                                           36 Fruit a capsule, dehiscent, dry at maturity.

                                                                                        42 Inflorescence a catkin, the flowers small (< 5 mm in diameter) and tightly arranged on the inflorescence axis (> 5 per cm of the axis)

                                                                                        42 Inflorescence various, but more diffuse, the flowers larger (> 5 mm in diameter, except for some flowers in Hydrangea in HYDRANGEACEAE) and loosely arranged (< 5 per cm of axis).

                                                                                           43 Capsule prominently 5-angled (star-shaped in ×-section)

                                                                                           43 Capsule not angled.

                                                                                             44 Inflorescence axillary, fascicled.

                                                                                               45 Capsule pink to red; fruits solitary or in axillary cymes

                                                                                               45 Capsule brown; fruits in axillary fascicles

                                                                                             44 Inflorescence terminal, a raceme, panicle, corymb, or compound cyme or thyrse.

                                                                                                 46 Inflorescence a flat-topped corymb or rounded compound cyme, as wide as or wider than long

                                                                                                 46 Inflorescence elongated, a raceme, panicle, or thyrse, much longer than wide.

                                                                                                   47 Capsule elongate (> 3× as long as wide), 8-25 mm long

                                                                                                   47 Capsule about as long as wide, 3-6 mm long.

                                                                                                     48 Sepal lobes 5

                                                                                                     48 Sepal lobes 4

1 Plants aerial and epiphytic, hemiparasitic shrubs (usually growing out of the branches of trees)

1 Plants terrestrial, autotrophic or hemiparasitic shrubs or subshrubs.

  2 Leaves succulent, nearly as thick as wide; [brackish to saline situations]

  2 Leaves herbaceous or leathery (succulent in Borrichia), much wider than thick; [various habitats].

    3 Creeping or short subshrubs, the stems primarily prostrate (< 2 dm tall), or spreading-ascending to decumbent and < 3 dm tall (MALPIGHIACEAE, in part; Galphimia primarily erect subshrubs to 1 m tall, of TX only in our area).

      4 Petals clawed, the bases noticeably thinned compared to the broader tips; fruit schizocarps, breaking into 2-3 nutlets or 1-seeded cocci; [in part, Aspicarpa and Galphimia]

      4 Petals not clawed, of relatively similar width from base to tip; fruit various, but never schizocarps of 2-3 nutlets or 1-seeded cocci.

        5 Well-developed leaves 4-6 per stem; inflorescence a head subtended by 4 large white bracts

        5 Well-developed leaves many per stem; inflorescence of individual flowers axillary in pairs or clusters or in terminal cymes.

          6 Flowers yellow; leaves with pellucid or dark punctate glands (use at least 10× magnification)

          6 Flowers white, pale pink, or deep pink; leaves lacking sessile, punctate glands.

             7 Leaves linear; flowers pale to deep pink, 5-merous

             7 Leaves orbicular or elliptic; flowers white to pale pink, 4-merous or 5-merous

               8 Leaves elliptic; flowers 5-merous; fruit a brownish capsule

               8 Leaves orbicular; flowers 4-merous; fruit a red berry

    3 Upright or scrambling shrubs, > 3 dm tall.

                 9 Scrambling shrubs, armed with recurved paired spines at the nodes (except Santalum, which can be a scrambling shrub and has red flowers producing drupe-like fruit bearing an apical circular rim).

                   10 Plants armed with recurved paired spines at the nodes; fruit ribbed, the ribs obviously glandular; petioles not 2-ribbed; flowers greenish-white to yellowish in color

                   10 Plants unarmed; fruit not ribbed, instead drupe-like and bearing a circular rim at the apex; petioles 2-ribbed; flowers red

                 9 Upright shrubs, unarmed.

                     11 Inflorescence a terminal head of many flowers.

                       12 Head spherical, lacking an involucre of conspicuous bracts or phyllaries

                       12 Head flattened, either subtended by 4 large white bracts or by an involucre with >5 green phyllaries.

                          13 Head subtended by 4 large white bracts; leaves with prominently parallel-arcing secondary veins; flowers 4-merous

                          13 Head subtended by an involucre of >5 green phyllaries; leaves with venation otherwise; flowers 5-merous

                     11 Inflorescence otherwise (if terminal, the flowers not arranged in heads), either of a solitary flower, or one of a wide variety of inflorescences with flowers attached at different points along branched or unbranched axes (e.g. axillary). {add: [Lagerstroemia] LYTHRACEAE; [Rosmarinus] LAMIACEAE; [Buxus] BUXACEAE; [Exochorda] ROSACEAE; various other [see spreadsheet]}

                            14 Inflorescence flat-topped (broader than long), terminal, a compound cyme or corymb.

                              15 Leaves distinctly 3-veined from the base, the 3 veins converging again at the leaf apex; [s. FL only in our area]

                              15 Leaves with prominently pinnate venation; [collectively widespread]

                                16 Leaves conspicuously glandular-punctate and aromatic; fruit a berry; ovary inferior; flowers with abundant stamens and a cup-shaped hypanthium; (partial; Mosiera, Myrcianthes, Syzygium).

                                16 Leaves not glandular-punctate and aromatic (only herbaceous Hypericum sometimes with black or transluscent leaf punctae, thus keyed instead in S1); flowers with 1-5 or 8-10 stamens; fruit not a berry, instead either a capsule (Hypericum), drupe (Cornus; Viburnum), follicle (APOCYNACEAE), or prominently ribbed and stipitate anthocarp (Pisonia).

                                  17 Fruit prominently ribbed (an anthocarp), the ribs with stipitate glands, the fruit thus usually sticky (this persisting on herbarium specimens)

                                  17 Fruit lacking prominent glandular ribs, the fruit not generally sticky.

                                    18 Fresh plants with white, milky juice; pistils 2, united only by the style and stigma; fruit a pair of linear or fusiform follicles, > 5-8× as long as thick, these variously shaped (terete, compressed, or prominently 3-angled)

                                    18 Fresh plants not exuding a white, milky latex (instead clear or not apparent); pistil 1 (or 2-5 in Hypericum); fruit various, but not of paired, linear follicles (see below).

                                       19 Flowers bright yellow; stamens many; leaves < 1.5 cm wide; fruit a capsule; leaves with pellucid or dark punctate glands (use at least 10× magnification)

                                       19 Flowers white or creamy; stamens 4-5; leaves > 1.5 cm wide; fruit a drupe; leaves lacking sessile, punctate glands.

                                         20 Petals 4; foliage with T-shaped hairs

                            14 Inflorescence either terminal, axillary or leaf-opposed, if terminal elongate (not flat-topped) or flowers solitary; if axillary then variously arranged (sometimes also solitary in the axils).

                                           21 Carpels many (> 9), either separate or fused; stamens many; perianth segments either many and undifferentiated into calyx and corolla, maroon, brown, or yellow (in CALYCANTHACEAE), or differentiated into a fleshy and persistent calyx of 5-9 sepals, and a deciduous corolla of 5-9 red (or white) petals (Punica in LYTHRACEAE).

                                             22 Fruit a wrinkled, 3-7 cm long, brown to black, elliptical aggregate of nearly spherical, large achenes; flowers solitary in axils; perianth segments many and undifferentiated into calyx and corolla, maroon, brown, or yellowish; ovary superior; branches unarmed

                                             22 Fruit a leathery, 4-15 cm in diameter, reddish, spherical berry with obpyramidal seeds surrounded by a juicy sarcotesta (pomegranate); perianth differentiated, the sepals fleshy and persistent on the fruit, the petals deciduous, 5-9, bright red to white; ovary inferior; branches typically armed with axillary spines

                                           21 Carpels 1-5 (-6), fused; stamens either 1-5 or 8-10 (except 10+ in MYRTACEAE); perianth segments 4-5 or 8, variously colored; fruit a simple capsule, drupe, or berry (including berry-like fruit); flowers 2-many, in axillary or terminal inflorescences OR sometimes solitary (MYRTACEAE, SANTALACEAE, and THESIACEAE); [Eudicots].

                                               23 Ovary inferior (flowers epigynous); corolla either absent, radially symmetrical, OR bilaterally symmetrical; fruit either a berry or a 1-seeded drupe (a berry or apically dehiscent capsule in MYRTACEAE).

                                                 24 Leaves conspicuously glandular-punctate and aromatic, evergreen and usually coriaceous; fruit a berry or apically-dehiscent capsule; flowers with abundant stamens and a cup-shaped hypanthium.

                                                 24 Leaves not both conspicuously glandular-punctate nor aromatic, membranous and deciduous; fruit a drupe or berry; flowers with 1-5 or 8-10 stamens, with or without a cup-shaped hypanthium.

                                                    25 Flowers unisexual and plants dioecious; corolla absent; pistillate flowers solitary, staminate flowers in pedunculate umbels or cymes, either terminal or axillary; fruit a 1-seeded drupe; leaves acute to acuminate at the apex

                                                      26 Inflorescences terminal

                                                      26 Inflorescences axillary

                                                    25 Flowers bisexual and plants hermaphroditic; corolla present; flowers paired, terminal or axillary, or in axillary spikes; fruit a berry; leaves rounded, obtuse, to acute (or acuminate in Lonicera maackii) at the apex

                                               23 Ovary superior (flowers hypogynous); corolla primarily radially symmetrical (zygomorphic in Citharexylum in VERBENACEAE and MALPIGHIACEAE; absent in Forestiera in OLEACEAE); fruit either a 1-4-seeded drupe, or a many-seeded berry (or berry-like fruit), or a capsule.

                                                        27 Leaves with a conspicuous mix of silvery stellate hairs (upper) and rusty colored scales (lower); ovaries bearing rusty colored scales; flowers small, yellowish and inconspicuous; [nw. PA northward]

                                                        27 Leaves glabrous or nearly so, lacking a conspicuous mix of stellate hairs adaxially and rusty scales abaxially; ovaries not bearing rusty colored scales; flowers of various size and color.

                                                          28 Stamens 8-10, of 2 different lengths in each flower; petals separate, 4-5 (-7), pink purple, 10-15 mm long; stems strongly arching, rooting at the tips; [plants of flooded to saturated wetlands]

                                                          28 Stamens either (1-) 2 (-4), or 4-5, or 10, all of the same length; petals fused (separate in RHAMNACEAE and BUXACEAE, but then < 5 mm long and white or cream), white, bright-yellow, lilac, or pink; stems erect (or at least not arching and rooting at the tips); [plants of various habitats].

                                                            29 Petals separate, 4-5, white or cream; stamens 4-5.

                                                              30 Petals clawed (the bases much thinner than the broader tips); fruit a drupe; inflorescence a terminal raceme (Byrsonima) or axillary corymbs or umbels (Malpighia); [in part, Byrsonima and Malpighia; some vining species will grow shrub-like, but those keyed in J3; TX and FL only in our area]

                                                              30 Petals not clawed, the width similar throughout; fruit a drupe or capsule; inflorescence axillary and terminal.

                                                                 31 Fruit a loculicidal capsule, dehiscing into 3 valves; branches square in ×-section; leaves < 2 cm long; [exotic, cultivated and weakly established, of temperate areas]

                                                                 31 Fruit a drupe with 2-4 pyrenes; branches round or nearly so in ×-section; leaves > 2 cm long; [natives, of peninsular FL]

                                                            29 Petals fused (at least basally), 4-5, white, bright yellow, lilac, or pink; stamens either (1-) 2 (-4) or 10; fruit either a capsule or a 1-seeded drupe.

                                                                   32 Inflorescence a drooping axillary raceme (sometimes minutely so), flowers zygomorphic; fruit a drupe

                                                                   32 Inflorescence various, if a raceme then not conspicuously drooping, flowers actinomorphic; fruit a drupe or capsule.

                                                                     33 Perianth 5-merous; corolla pink; stamens 10; fruit a 5-locular capsule

                                                                     33 Perianth 4-merous; corolla white, bright yellow, or lilac; stamens (1-) 2 (-4); fruit either a 1-seeded drupe or a 2-locular capsule