1 Stems, and often leaves, prickly and/or spiny.

..2 Shrubs to 3.5 m tall; leaves sessile; leaves paired and of different sizes

..2 Herbs to 2 (-3) m tall or shrubs, small trees, or scrambling, vine-like shrubs to 5 m tall or long; leaves petiolate; leaves not paired.

....3 Shrubs, small trees, or scrambling, vine-like shrubs to 5 m tall or long; stems with strongly recurved prickles.

......4 Berry red, < 1 cm in diameter; corolla lobed nearly to the base, rotate

......4 Berry yellow, 1.0-1.5 cm in diameter; corolla shallowly lobed, the sinuses < ½ of the way to the base

....3 Herbs to 2 (-3) m tall; stems with straight prickles; stems with prickles, but these not strongly recurved.

........5 Berry 2.5-5 cm long, densely hirsute with hairs (2-) 3-5 mm long

........5 Berry 0.5-5 cm long, glabrous or pubescent with hairs < 1 mm long.

..........6 Berry enveloped at least until near maturity by prickly calyx; leaves regularly and strongly pinnately parted or very deeply divided (sinus depth greater than 1/2 distance from leaf margin to midvein).

............ 7 Corolla yellow; inflorescence stellate-pubescent only; calyx tightly enveloping the fruit; seeds coarsely undulate-rugose

............ 7 Corolla violet to (rarely) white, anthers all similar; inflorescence glandular-villous and stellate-pubescent; calyx loosely or tightly enveloping the fruit; seeds minutely reticulate-pitted.

............ ..8 Anthers unequal, the lowest violet-tinged, longer, and incurved; fruiting pedicels erect; berry enclosed by the closely fitting and often adhering calyx

............ ..8 Anthers about equal, all yellow; fruiting pedicels spreading; berry loosely enclosed by the calyx

..........6 Berry not enveloped by prickly calyx; the leaves not pinnately parted or divided (except in S. sisymbriifolium), or only weakly so (sinus depth < ½ the distance from leaf margin to midvein).

............ ....9 Berry (1.5-) 2-5 cm long; lower leaf surface pubescent with simple hairs, these viscid (gland-tipped) or not.

............ ......10 Ripe berry orange-red to reddish, leaves deeply lobed (sinus depth up to 1/2 distance from leaf margin to midvein); plants with eglandular, villous pubescence; seeds winged

............ ......10 Ripe berry yellow, immature berry green with white mottles, leaves shallowly lobed (sinus depth typically < 1/3 distance from leaf margin to midvein); plants glandular-viscid; seeds not winged

............ ....9 Berry < 2 cm in diameter; lower leaf-surface stellate-pubescent.

............ ........11 Leaves linear-lanceolate, 1-3 cm wide, trichome clusters 0.5 mm broad, with 12 or more rays

............ ........11 Leaves ovate to elliptic, 2-8 cm wide, often lobed or cleft, trichome clusters 1 mm broad, with 5-10 rays.

............ ..........12 Leaves pinnately parted or divided, the segments often pinnately lobed; calyx enveloping fruit when ripe, berry red; plant annual

............ ..........12 Leaves irregularly lobed or cleft, the lobes or segments entire; calyx not enveloping fruit when ripe; berry yellowish orange, never red; plant perennial.

............ ............ 13 Stellate trichomes of lower leaf surface stipitate, the 6-8 rays, the central one as long as or shorter than the lateral rays, of 1 cell; corolla 3-4 cm wide, calyx 8-12 mm long

............ ............ 13 Stellate trichomes of lower leaf surface sessile, with 2-5 rays, the central one elongate, of 1-5 cells, and longer than the lateral rays; corolla 2-3 cm wide, calyx 5-7 mm long.

............ ............ ..14 Leaves entire, margins at most sinuate; plants up to 2 dm in stature; prickles few, absent, and/or confined to midveins; corollas white; inflorescence with up to ca. 4 flowers; [rare plants of c. AL and wc. GA]

............ ............ ..14 Leaves not entire, lobed, cleft, pinnately parted, or divided; plants 3-10 dm in stature; prickles more abundant and generally distributed; corollas purple, rarely white; inflorescence with up to ca. 15 flowers; [plants more widely distributed, weedy or ruderal].

............ ............ ....15 Stems sparsely to moderately armed with prickles up to 12 mm long; inflorescences 2- to several-branched; corollas 2.0-4.4 cm in diameter; [mainly AL, FL, and GA, rarely MS]

............ ............ ....15 Stems unarmed or sparsely armed with prickles up to 6 mm long; inflorescences unbranched or once branched; corollas 2.2-3.0 cm in diameter; [collectively widespread].

............ ............ ......16 Leaf margins deeply lobed to parted; sinuses of lobes reaching more than half the distance to the midvein or almost to the midvein; apex of leaf lobes typically rounded; [s. GA and FL]

............ ............ ......16 Leaf margins subentire, sinuate, or lobed; sinuses of lobes, when present, reaching less than half the distance to the midvein; apex of leaf lobes subacute to acute, sometimes rounded; [widespread]

1 Stems and leaves not prickly or spiny.

............ ............ ........17 Leaves compound (at least well-developed leaves), pinnatifid, or basally auriculate-lobed.

............ ............ ..........18 Woody or suffrutescent climbing or twining vine; leaves regularly pinnatifid (to bipinnatifid) or basally auriculate-lobed.

............ ............ ............ 19 Leaves with 2 basal lobes or leaflets much smaller than the terminal one (some upper leaves simple); [mainly northwards]

............ ............ ............ 19 Leaves pinnately to bipinnately deeply lobed, usually with 3-9 lobes of relatively equal size; [peninsular FL]

............ ............ ..........18 Herb, not twining; leaves pinnately compound or pinnatifid.

............ ............ ............ ..20 Leaves sessile or short-petiolate, 1-5 cm long, regularly pinnatifid, the lobes similar in size and shape; plant more or less prostrate

............ ............ ............ ..20 Leaves distinctly petiolate, 10-40 cm long, pinnately or bipinnately compound, the lateral leaflets ovate, often with smaller leaflets intercalated between the main leaflets; plant erect, scrambling, or sprawling.

............ ............ ............ ....21 Stem pubescence glandular; anthers opening by longitudinal slits; seeds hairy; [tomato]

............ ............ ............ ....21 Stem pubescence eglandular; anthers opening by terminal pores; seeds glabrous; [potato]

............ ............ ........17 Leaves not compound or auriculate-lobed.

............ ............ ............ ......22 Shrubs and small trees; [mainly FL and s. TX southwards, rarely northwards].

............ ............ ............ ........23 Berry stellate-pubescent; [FL and s. TX southwards].

............ ............ ............ ..........24 Leaves of new growth with stipule-like auricled miniature leaves at the petiole base; corolla lavender to deep purple; [collectively widespread]

............ ............ ............ ..........24 Leaves lacking associated stipule-like small leaves; corolla white.

............ ............ ............ ............ 25 Leaf blade broadest below the midpoint, short-cuneate or nearly truncate at the base; calyx and corolla densely short-stellate pubescent

............ ............ ............ ............ 25 Leaf blade broadest above the midpoint, narrowly cuneate at the base; calyx and corolla shaggy-pubescent with stellate hairs

............ ............ ............ ........23 Berry glabrous; [mainly FL and s. TX southwards, rarely northwards].

............ ............ ............ ............ ..26 Plants glabrous or if sparsely pubescent, the hairs simple.

............ ............ ............ ............ ....27 Leaves glaucous; Inflorescence a branched raceme

............ ............ ............ ............ ....27 Leaves green; inflorescence a congested cyme borne opposite a leaf

............ ............ ............ ............ ..26 Plants stellate-pubescent.

............ ............ ............ ............ ......28 Flowers 1-3 in an axillary fascicle.

............ ............ ............ ............ ........29 Leaf blades tapered to base; leaf blades widest at or above the midpoint; [alien]

............ ............ ............ ............ ........29 Leaf blades cordate or truncate at base; leaf blades widest near the base; [native, TX]

............ ............ ............ ............ ......28 Flowers either in a simple to compound cyme, or in a racemiform cyme.

............ ............ ............ ............ ..........30 Inflorescence a racemiform cyme

............ ............ ............ ............ ..........30 Inflorescence a simple or compound cyme

............ ............ ............ ......22 Herbs; [collectively widespread].

............ ............ ............ ............ ............ 31 Corolla 10-16 mm long, lavender; fruits 10-15 mm in diameter, yellow when ripe (blackening with age); trichomes of stems and leaves stellate, with 9-13 branches

............ ............ ............ ............ ............ 31 Corolla 5-8 mm long, white to cream; fruits 5-10 mm in diameter, black, purple, green, orange, red, or dark yellow when ripe; trichomes of stems and leaves simple (when present).

............ ............ ............ ............ ............ ..32 Foliage with glandular trichomes; fresh plants sticky to the touch.

............ ............ ............ ............ ............ ....33 Mature berry orange, red or dark yellow, usually somewhat ellipsoid; calyx lobes with translucent sinuses

............ ............ ............ ............ ............ ....33 Mature berry green, purple or black, usually globose or subglobose; calyx lobes without translucent sinuses.

............ ............ ............ ............ ............ ......34 Calyx lobes not enlarged and enclosing the berry

............ ............ ............ ............ ............ ......34 Calyx lobes enlarged in fruit and enclosing the berry.

............ ............ ............ ............ ............ ........35 Leaf bases attenuate to cuneate; inflorescences mostly internodal, with 4-8 (-10) flowers; corolla with a central greenish yellow star with black or purple margins; berries dark green to greenish brown, marbled with white, becoming translucent and shiny; stone cells 1-3, ca. 0.5 mm in diameter

............ ............ ............ ............ ............ ........35 Leaf bases cordate or truncate; inflorescences mostly leaf-opposed, with 2-5 (-7) flowers; corolla with a central greenish yellow star without black or purple margins; berries pale green, not marbled with white, becoming matte, opaque; stone cells 4-6, 0.8-1 mm in diameter

............ ............ ............ ............ ............ ..32 Foliage lacking glandular trichomes, sometimes with a few scattered trichomes with glandular tips, but not markedly glandular (fresh plants not sticky to the touch).

............ ............ ............ ............ ............ ..........36 Leaves deeply pinnatifid; prostrate herbs with fleshy leaves

............ ............ ............ ............ ............ ..........36 Leaves with entire or various toothed margins, not pinnatifid; plants erect or scrambling (rarely prostrate, if so, the leaves NOT fleshy).

............ ............ ............ ............ ............ ............ 37 Mature berries orange, red or dark yellow (shiny and translucent at maturity); calyx lobes with translucent sinuses

............ ............ ............ ............ ............ ............ 37 Mature berries green, purple or black; calyx lobes without translucent sinuses.

............ ............ ............ ............ ............ ............ ..38 Anthers less than or equal to 2 mm long.

............ ............ ............ ............ ............ ............ ....39 Mature berries dropping without the pedicel; calyx lobes strongly reflexed in fruit; stone cells 0-2 (-4)

............ ............ ............ ............ ............ ............ ..38 Anthers more than 2 mm long

............ ............ ............ ............ ............ ............ ......40 Buds narrowly ellipsoid to narrowly ovoid; corolla deeply stellate with narrowly lanceolate strap-like lobes; berries shiny, with > 10 stone cells; prostrate herbs

............ ............ ............ ............ ............ ............ ......40 Buds ellipsoid to ovoid to obovoid; corolla stellate with triangular to deltate lobes, not markedly lanceolate and strap-like; berries matte or somewhat shiny, usually with < 10 stone cells; erect or straggling herbs

............ ............ ............ ............ ............ ............ ........41 Stone cells present in mature berries, always more than 2; corolla (10-) 15-20 mm in diameter

............ ............ ............ ............ ............ ............ ..........42 Anthers (2.7-) 3-4.5 mm long, slightly tapering to the tip; buds ovoid, tapering to the apex; free portion of the filaments minute, ca. 1/4 the length of the anther; corolla to 20 mm in diameter

............ ............ ............ ............ ............ ............ ..........42 Anthers less than 3 mm long, ellipsoid with straight sides; buds ellipsoid; free portion of the filaments half the length of the anthers; corolla < 15 mm in diameter.

............ ............ ............ ............ ............ ............ ............ 43 Basal flower in the inflorescence with the articulation above the rachis; calyx lobes unequal, lanceolate, the longest one 1.7-4.5 mm long; seeds 1.8-2 mm long; stone cells 2-4; [prairies and open woodlands, mw. US]

............ ............ ............ ............ ............ ............ ............ 43 All flowers with the articulation at the inflorescence rachis; calyx lobes equal, deltate, 0.5–1 mm long; seeds 1.2-1.5 mm long; stone cells usually > 5; [forests and coastal areas, se. US]

............ ............ ............ ............ ............ ............ ........41 Stone cells in mature berries absent (occasionally 2); corolla < 15 mm in diameter.

............ ............ ............ ............ ............ ............ ............ ..44 Berries 10-20 mm in diameter, shiny, slightly flattened; fruiting pedicels strongly spreading; anthers somewhat tapering, often drying brownish orange; [cultivated, perhaps a waif]

............ ............ ............ ............ ............ ............ ............ ..44 Berries < 15 mm in diameter, somewhat shiny, matte or slightly glaucous, globose; fruiting pedicels weakly spreading or more usually deflexed; anthers ellipsoid, not drying brownish orange; [native, adventive, or naturalized].

............ ............ ............ ............ ............ ............ ............ ....45 Inflorescences with the flowers spaced along the rachis; anthers 1.8–2.5 mm long; fruiting pedicels spreading; berry surface slightly shiny; seeds 1.8-2 mm long

............ ............ ............ ............ ............ ............ ............ ....45 Inflorescences with the flowers clustered at the tips (sub-umbelliform), only a few spaced along the rachis; anthers > 2 mm long; fruiting pedicels deflexed, usually strongly so; berry surface matte or glaucous; seeds 1-1.5 mm long.

............ ............ ............ ............ ............ ............ ............ ......46 Peduncle in fruit at right angles or more usually strongly deflexed downwards; berries 4-9 mm in diameter; calyx lobes appressed to surface of berry in fruit; styles exserted to 1.5 mm from the anther cone at anthesis; [adventive in our area]

............ ............ ............ ............ ............ ............ ............ ......46 Peduncle in fruit slightly ascending, not deflexed downward; berries 8-14 mm in diameter; calyx lobes reflexed in fruit; style exserted 2-2.5 mm from the anther cone at anthesis; [coastal habitats, native in our area]