Analytical key to the species of Datura occurring in Tunisia

1. Leaves sinuately dentate to pinnately lobed; fruit (capsule) erect; seeds without elaiosome........ 2

– Leaves unequally dentate to almost entire; fruit (capsule) never erect; seeds with elaiosome......... 3

2. Fruit with numerous, ± equal, evenly distributed spines..................... D. stramonium L.

– Fruit with few, unequal, stout, unevenly distributed spines (longer at fruit apex).......... D. ferox L.

3. Leaves glabrous; fruit spines short, blunt, sometimes reduced to bumps; corolla commonly with 2 verticils (flore pleno) and purple on outer surface........................................ D. metel L.

– Leaves pubescent; fruit spines not reduced, sharp to touch; corolla with 1 verticil and not purple on outer surface.................................. 4

4. Corolla outer surface glabrous..... D. inoxia Mill.

– Corolla outer surface pubescent.. D. wrightii Regel