Leaves usually alternate, sometimes paired, simple or pinnate, margins entire or lobed, petiolate.
Inflorescences cyme-like, often becoming raceme-like, subumbellate or panicle-like, terminal, lateral, axillary, extra-axillary or leaf-opposed. Flowers usually bisexual, actinomorphic or slightly zygomorphic. Calyx campanulate, rotate or cup-shaped, usually 5-lobed. Corolla stellate and deeply incised to rotate, rarely campanulate, purple, blue, white or yellow, usually 5-lobed. Stamens 5, usually equal, inserted in throat of corolla; anthers 2-locular, basifixed, cohering and cone-like around style or not cohering, dehiscing by terminal pores or slits. Ovary mostly 2-locular; stigma terminal, capitate or bifid.
Fruit a succulent or bony berry, ± globose. Occurs in all habitats except alpine, aquatic and saline. Many occur as weeds. Cosmopolitan.
| | Key to the species | |
| 1 | Prickles absent | 2 |
| Prickles present | 25 |
| 2 | Climbing or sprawling herbs and shrubs | 3 |
| Herbs, shrubs or small trees, usually erect, never climbing
Back to 1 | 6 |
| 3 | Anthers dehiscing by terminal pores only | 4 |
| Anthers dehiscing by terminal pores and lateral slits
Back to 2 | 5 |
| 4 | Leaves 3-lobed, lobes entire; berry yellow-green, 4–5 mm diam.; branches frequently rooting at nodes | Solanum radicans |
| Leaves 7–9-lobed, lobes toothed; berry marbled whitish green, 8–12 mm diam.; branches not rooting at nodes
Back to 3 | Solanum triflorum |
| 5 | Leaves entire (juvenile leaves deeply lobed); berry 7–9 mm diam.; seeds glabrous | Solanum jasminoides |
| Leaves usually 3–9-lobed; berry 10–12 mm diam.; seeds hairy
Back to 3 | Solanum seaforthianum |
| 6 | Corolla white or white with a purple tinge and yellow-green centre | 7 |
| Corolla pale blue, blue-violet, violet to deep purple-blue
Back to 2 | 14 |
| 7 | Calyx 1–3.5 mm long | 8 |
| Calyx 4–5 mm long
Back to 6 | 13 |
| 8 | Shrubs to 3 m high; leaves glabrous except for tufts of hairs in axils of veins on lower surface; berry bright orange-yellow | Solanum spirale |
| Soft-wooded annual or short-lived perennial herbs, usually less than 1 m high; leaves glabrous or with hairs not restricted to vein axils; berry purple-black, green or reddish
Back to 7 | 9 |
| 9 | Mature berry black or red | 10 |
| Mature berry green
Back to 8 | 12 |
| 10 | Fruiting peduncle sharply deflexed from its base | Solanum chenopodioides |
| Fruiting peduncle erect ascending or curved downwards
Back to 9 | 11 |
| 11 | Mature berry shiny; seeds usually more than 40 per fruit, 1–1.5 mm long | Solanum americanum |
| Mature berry dull; seeds usually 20–35 per fruit, 1.8–2.2 mm long
Back to 10 | Solanum nigrum |
| 12 | Indumentum of glandular hairs; calyx lobes 2–4 mm long and 2–5 mm wide in fruit; berry 5–8 mm diam | Solanum physalifolium |
| Indumentum predominantly of non-glandular hairs; calyx lobes 1–2.5 mm long and less than 2 mm wide in fruit; berry 8–10 mm diam
Back to 9 | Solanum opacum |
| 13 | Petioles 1–10 cm long; inflorescences branched, many-flowered; peduncle to first fork 3–8 cm long; berry dull yellow; densely and softly hairy, with hairs stellate to bristly | Solanum erianthum |
| Petioles 0.5–1.5 cm long; inflorescences unbranched, short, 1–few-flowered; peduncle 0–1 cm long; berry bright orange-red; glabrous or sparsely hairy with hairs simple or branched but not stellate
Back to 7 | Solanum pseudocapsicum |
| 14 | Leaves with 1 or 2 small sessile stipule-like leaves at base of petiole | Solanum mauritianum |
| Leaves lacking additional small stipule-like leaves
Back to 6 | 15 |
| 15 | Entire leaves usually more than 10 times long as broad (undulate to lobed leaves also present) | 16 |
| Entire leaves 2–8 times long as broad (usually with undulate to lobed leaves also present)
Back to 14 | 17 |
| 16 | Fruiting pedicels mostly less than 3 cm long; berry 15–20 mm diam., ochre-yellow with purple markings | Solanum linearifolium |
| Fruiting pedicels mostly 3–5 cm long; berry 20–25 mm diam., greenish ivory
Back to 15 | Solanum vescum |
| 17 | Lobed leaves deeply lobed; corolla 20–30 mm diam.; berry green or tinged purple | Solanum simile |
| Lobed leaves undulate to shallowly lobed or all leaves entire; corolla 15–40 mm diam.; berry white, greenish white, yellowish, bright red to brownish black
Back to 15 | 18 |
| 18 | Plant hairy, often densely so, with stellate hairs | 19 |
| Plant glabrous except for minute glandular hairs on young points, corolla apices and buds
Back to 17 | 24 |
| 19 | Berry bright red, 5–8 mm diam | 20 |
| Berry white, greenish white, yellowish or brown-black, 10–20 mm diam
Back to 18 | 21 |
| 20 | Leaves 6–9 cm long, 3–5 cm wide; petioles more than 1 cm long | Solanum densevestitum |
| Leaves 3–6 cm long, 1.5–2.5 cm wide; petioles less than 1 cm long
Back to 19 | Solanum nemophilum |
| 21 | Leaves with upper surface sparsely hairy or glabrous | 22 |
| Leaves with upper surface densely hairy
Back to 19 | 23 |
| 22 | Leaves lanceolate, with lower surface woolly; berry 15–20 mm diam | Solanum brownii |
| Leaves more or less oblong, with lower surface densely hairy, but not woolly; berry 10–15 mm diam
Back to 21 | Solanum tetrathecum |
| 23 | Berry dry, yellow maturing to brown | Solanum sturtianum |
| Berry succulent, yellow to light yellow-brown
Back to 21 | Solanum esuriale |
| 24 | Corolla lobes acute; berry orange-red to scarlet | Solanum aviculare |
| Corolla lobes notched; berry orange-yellow
Back to 18 | Solanum laciniatum |
| 25 | Hairs predominately simple or glandular, or hairs absent | 26 |
| Hairs predominately stellate
Back to 1 | 29 |
| 26 | Corolla stellate and deeply incised; leaves broad-ovate; berry 20–35 mm diam., bright orange-red | Solanum capsicoides |
| Corolla campanulate, stellate and shallowly incised, or rotate; leaves ovate or elliptic; berry 10–25 mm diam., usually green, yellow or white
Back to 25 | 27 |
| 27 | Fruiting calyx largely enclosing berry, sometimes splitting | Solanum hystrix |
| Fruiting calyx not enclosing berry
Back to 26 | 28 |
| 28 | Leaves glabrous or very sparsely hairy, with lobes cut to more than two-thirds of the way to midvein | Solanum papaverifolium |
| Leaves hairy, with lobes cut less than two-thirds of the way to midvein
Back to 27 | Solanum adenophorum |
| 29 | Fruiting calyx surrounding or enclosing at least three-quarters of berry | 30 |
| Fruiting calyx not surrounding berry
Back to 25 | 35 |
| 30 | Berry mostly enclosed in or surrounded by lobes of persistent calyx | 31 |
| Berry mostly enclosed in enlarged calyx tube
Back to 29 | 34 |
| 31 | Berry red | 32 |
| Berry green, yellow or white
Back to 30 | 33 |
| 32 | Leaves lobed, lower lobes often forming leaflets; corolla white or pale blue; berry 15–20 mm diam.; fruiting calyx prickly | Solanum sisymbriifolium |
| Leaves entire or almost so when mature, juvenile leaves shallowly lobed; corolla violet or purple; berry 5–8 mm diam.; fruiting calyx not prickly
Back to 31 | Solanum densevestitum |
| 33 | Glandular and stellate hairs present on all parts | Solanum campanulatum |
| Glandular hairs absent or confined to calyx
Back to 31 | Solanum petrophilum |
| 34 | Flowers yellow, zygomorphic; berry erect, dry and papery | Solanum rostratum |
| Flowers purple, actinomorphic; berry usually pendent, not dry and papery
Back to 30 | Solanum karsense |
| 35 | Berry red, orange-red or blackish red, never brownish | 36 |
| Berry green, whitish, yellow or purple, often drying to yellow- or orange-brown, brown or black
Back to 29 | 45 |
| 36 | Leaves entire sometimes sinuate (in Solanum elegans), if basal lobes present, then linear | 37 |
| Leaves lobed, at least in part, and broad, never linear
Back to 35 | 41 |
| 37 | Leaves linear to lanceolate, 0.2–2 cm wide | 38 |
| Leaves ovate, broad-ovate or elliptic, 1–14 cm wide
Back to 36 | 40 |
| 38 | Leaves concolorous or slightly discolorous, usually prickly, often with 2 basal lobes | Solanum ferocissimum |
| Leaves distinctly discolorous, with few or no prickles, rarely with basal lobes
Back to 37 | 39 |
| 39 | Corolla deeply stellate, 10–15 mm diam.; berry 5–8 mm diam | Solanum parvifolium |
| Corolla shallowly stellate, 25–30 mm diam.; berry 10–15 mm diam
Back to 38 | Solanum elegans |
| 40 | Leaves distinctly discolorous, sparsely hairy on upper surface | Solanum stelligerum |
| Leaves slightly discolorous, densely hairy on upper surface
Back to 37 | Solanum nemophilum |
| 41 | Corolla 10–20 mm diam | 42 |
| Corolla 25–35 mm diam
Back to 36 | 44 |
| 42 | Branches with scattered prickles | Solanum chenopodinum |
| Branches densely to moderately prickly
Back to 41 | 43 |
| 43 | Plant hairs with stellate and minutely glandular hairs; upper leaf surface sparsely hairy; corolla bluish purple; seeds pale brown | Solanum stelligerum |
| Plant hairy with stellate hairs only; upper leaf surface glabrous or with hairs confined to veins; corolla white or violet; seeds pale yellow or pale orange
Back to 42 | Solanum corifolium |
| 44 | Pedicels and calyx with stellate hairs only | Solanum elegans |
| Pedicels and calyx with stellate, simple and glandular hairs
Back to 41 | Solanum inaequilaterum |
| 45 | Leaves distinctly lobed usually at least 1/4 way to midvein | 46 |
| Leaves entire or shallowly lobed
Back to 35 | 52 |
| 46 | Hairs dense to moderately dense on upper leaf surface | Solanum adenophorum |
| Hairs sparse on upper leaf surface
Back to 45 | 47 |
| 47 | Anthers 2–2.5 mm long | Solanum prinophyllum |
| Anthers 3–6 mm long
Back to 46 | 48 |
| 48 | Leaves concolorous or slightly discolorous; berry 20–30 mm diam | 49 |
| Leaves usually distinctly discolorous; berry 10–25 mm diam
Back to 47 | 50 |
| 49 | Berry yellow; inflorescence a 1–3-flowered cluster | Solanum pungetium |
| Berry yellow, maturing to brown or black; inflorescence a 1–6-flowered raceme
Back to 48 | Solanum linnaeanum |
| 50 | Prickles bright red or orange-red; flowering calyx lobes 1–2 mm long; berry 10–15 mm diam | Solanum lacunarium |
| Prickles pale yellow or pale orange; flowering calyx lobes 2.5–5 mm long; berry 15–25 mm diam
Back to 48 | 51 |
| 51 | Lower leaf surface densely woolly; flowering calyx lobes triangular | Solanum brownii |
| Lower leaf surface densely hairy, not woolly; flowering calyx lobes usually linear
Back to 50 | Solanum cinereum |
| 52 | Leaves broad-ovate, 0.8–2 cm long | Solanum oligacanthum |
| Leaves oblong to narrow-ovate, ovate or elliptic (juvenile leaves of Solanum furfuraceum broad-ovate, to 17 cm long and to 12 cm wide), mostly more than 2 cm long
Back to 45 | 53 |
| 53 | Leaves shallowly lobed | 54 |
| Leaves entire and usually slightly undulate, or sinuate
Back to 52 | 58 |
| 54 | Leaves with upper surface sparsely hairy, often distinctly discolorous | 55 |
| Leaves with upper surface densely hairy, concolorous or slightly discolorous
Back to 53 | 56 |
| 55 | Lower leaf surface densely woolly, hairs pale yellow or pale green; seeds 2.5–3.5 mm long; leaves usually narrow-ovate | Solanum brownii |
| Lower leaf surface moderately woolly or not woolly, hairs bright yellow or rusty; seeds 1.5–2 mm long; leaves usually broad-ovate
Back to 54 | Solanum furfuraceum |
| 56 | Prickles usually red; leaves silvery green; flowering peduncle ± 10 mm long; anthers 5–8 mm long | Solanum elaeagnifolium |
| Prickles never red; leaves grey-green or pale green, occasionally rusty-green; flowering peduncle 5–40 mm long; anthers 2.5–5 mm long
Back to 54 | 57 |
| 57 | Leaves 1–4 cm wide; corolla 10–15 mm diam., pale lavender, often remaining closed; anthers 2.5–3 mm long | Solanum cleistogamum |
| Leaves 0.5–1.5 cm wide; corolla 15–25 mm diam., purple; anthers 4–5 mm long
Back to 56 | Solanum esuriale |
| 58 | Upper leaf surface sparsely hairy or glabrous | 59 |
| Upper leaf surface densely hairy
Back to 53 | 61 |
| 59 | Leaves ovate to elliptic, less than 2.5 times long as broad | Solanum furfuraceum |
| Leaves oblong or narrow-ovate, more than 2.5 times long as broad
Back to 58 | 60 |
| 60 | Leaves narrow-ovate, with lower surface woolly; berry 15–20 mm diam | Solanum brownii |
| Leaves more or less oblong, with lower surface not woolly; berry 10–15 mm diam
Back to 59 | Solanum tetrathecum |
| 61 | Berry dry, yellow maturing to brown-black | Solanum sturtianum |
| Berry bony or succulent, yellow, green, purple or orange-brown
Back to 58 | 62 |
| 62 | Berry hard and bony, often with lower half enclosed by calyx; prickles abundant on calyx | Solanum quadriloculatum |
| Berry succulent, with lower half not enclosed by calyx; prickles absent from calyx (except Solanum cleistogamum)
Back to 61 | 63 |
| 63 | Berry pale yellow-green, often with purple tinge; branches sprawling or prostrate | 64 |
| Berry yellow, yellow-brown or orange-brown; branches usually erect, rarely sprawling
Back to 62 | 65 |
| 64 | Corolla 10–15 mm long; anthers 2.5–3 mm long; berry 10–13 mm diam | Solanum cleistogamum |
| Corolla 20–30 mm long; anthers 4.5 mm long; berry 15–20 mm diam
Back to 63 | Solanum ellipticum |
| 65 | Peduncles 10–40 mm long; berry ovoid, obovoid or almost globose, with apex acute | Solanum esuriale |
| Peduncles to 10 mm long; berry globose or depressed-globose
Back to 63 | 66 |
| 66 | Flowering calyx lobes awl-shaped; calyx 9–10 mm long | Solanum elaeagnifolium |
| Flowering calyx lobes triangular; calyx 4–8 mm long
Back to 65 | 67 |
| 67 | Prickles 2–5 mm long; pedicels 10–15 mm long; seeds pale brown | Solanum coactiliferum |
| Prickles to 10 mm long; pedicels usually 5–10 mm long; seeds light grey
Back to 66 | Solanum tetrathecum |
