Identification key to the species of Aethionema

1. Seeds 3 or more ..................................................................................................................................................................................2

- Seeds 1 or rarely 2 ..............................................................................................................................................................................3

2. Inflorescence compact, not or scarcely heterocarpic; fruits adpressed ..............................................................................................4

4. Style 2–4 mm; petals 4.5–6 mm ......................................................................................................................................... A. froedinii

- Style less than 1 mm; petals 2–4 mm .................................................................................................................................................5

5. Petals 2–3 mm ................................................................................................................................................................. A. arabicum

- Petals c. 4 mm ............................................................................................................................................................ A. heterocarpum

3. Inflorescence ± loose, clearly heterocarpic; fruits held ± horizontally ..............................................................................................6

6. Tall growing plants, 10–20 cm .............................................................................................................................................. A. dumanii

- Low growing plants, 3–6 cm .............................................................................................................................................. A. gypsicola