Solanaceae

1. Anthers forming a tight, conical column around style. Anthers yellow to orange, opening by apical pores === Solanum (incl. Lycopersicon)

1. Anthers held otherwise, never tightly surrounding (and largely obscuring) the style. Anthers opening by longitudinal slits === 2

2. Woody shrub, usually with spiny twigs. Corolla purplish. Fruit a bright red berry === Lycium

2. Herbaceous annual, biennial or perennial, never with spiny twigs. Corolla variably coloured. Fruit a capsule or a berry === 3

3. Fruit a berry, sometimes included in the inflated calyx === 4

3. Fruit a dry capsule === 8

4. Berry completely enclosed by inflated, strongly accrescent calyx === 5

4. Berry free, calyx not accrescent === 6

5. Calyx lobes free. Corolla blue to mauve, ca. 25-40 mm across === Nicandra

5. Calyx lobes fused at margin. Corolla yellowish or whitish, usually smaller === Physalis

6. Inflorescence umbel-like (2-8-flowered), on a distinct peduncle. Fruit a shiny black berry. Corolla greenish yellow === Jaltomata

6. Flowers solitary, axillary. Fruit variably coloured (greenish, yellowish, reddish or black). Corolla never greenish yellow === 7

7. Berry globose, black. Corolla brownish violet to greenish, 25-30 mm across. Perennial (native) === Atropa

7. Berry of variable shape and variably coloured (greenish, yellowish or reddish) but never black and globose. Corolla white, 10-20 mm across. Annual === Capsicum

8. Fruit nearly always a spiny capsule (rarely spineless), 30-80 mm long === Datura

8. Fruit never spiny, always smaller === 9  

9. Fertile stamens 4 === Salpiglossis

9. Fertile stamens 5 === 10

10. Capsule opening by a circumscissile line near apex === Hyoscyamus

10. Capsule opening by valves === 11  

11. Calyx divided nearly to base. Flowers always solitary. Corolla campanulate === Petunia

11. Calyx divided at most to ½ way to base. Flowers in a panicle-like or racemose inflorescence. Corolla tubular or funnel-shaped, abruptly expanding near apex === Nicotiana