Key to Lepidium species

1. Lower leaves 2-pinnatisect, cauline leaves ovate to cordate....................... 7. L. perfoliatum .

- Lower leaves entire, pinnatifid or pinnatisect, cauline leaves pinnatifid, pinnatisect or entire.................................................................2.

2. Silicula equal in length to the pedicel or longer than pedicel.......................................................3.

- Silicula shorter than pedicel...........................4.

3.Cauline leaves entire, sessile, amplexicaul, auriculate,valves rough,papillate.... 1. L. campestre .

- Cauline leaves pinnatifid or pinnatisect, with stalk, not auriculate, valves smooth......................... ..................................................... 2. L. sativum .

4. Leaves entire, cauline leaves elliptic to ovate, silicula not winged.................... 8. L. latifolium .

- Lower leaves pinnatifid or pinnatisect, cauline leaves oblong lanceolate to lanceolate or linear, silicula winged or not winged......................... 5.

5.Silicula not winged................ 6. L. pinnatifidum .

- Silicula narrowly winged or broadly winged .. 6.

6. Petals longer than sepals......... 3. L. virginicum .

- Petals equal to sepals or absent..................... 7.

7. Silicula obovate to suborbicular, upper part broadly winged, wing corner obtuse, notch deep ............................................... 4. L. densiflorum .

- Silicula elliptic to ovoid, upper part narrowly winged, wing corner acute, notch shallow ......... ...................................................... 5. L. ruderale .