BRASSIACEAE. 151 



Pod orbicular ; valves convex, with flattened margins ; filaments dilated 



and toothed near the base. 19. ALLYSSUM. 



Pod oblong, ovate or linear, rarely nearly orbicular ; valves flat, or if 



convex not with flattened margins ; filaments unappendaged. 

 Valves nerveless. 

 Valves not elastically dehiscent ; seeds in two rows ; pod usually short. 



20. DRABA. 

 Valves elastically dehiscent ; seeds in one row ; pod long. 



21. CARDAMINE. 

 Valves nerved and reticulate, not elastically dehiscent. 



Pod short, from orbicular to linear-oblong. 20. DRABA. 



Pods elongated-linear. 



Cotyledons accumbent. 22. ARABIS. 



Cotyledons incumbent. 23. CONRINGIA. 



2. Anthers sagittate at the base. 



Calyx campanulate, open ; petals ample. 



Pod flat. 24. STREPTANTHUS. 



Pod terete or tetragonal. 26. THELYPODIUM. 



Calyx urn-shaped, closed ; blades of the petals narrow, undulate-crisp. 



25. EUKLISIA. 



II. Pod terete long-stipitate ; sepals spreading in anthesis ; anthers curved and 

 spirally twisted. 27. STANLEYA. 



i. CARDARIA Desv. 



i. Cardaria Draba (L.) Desv. (Lepidium Draba L.) Introduced from 

 Europe; in waste places from Wyo. to Colo, and Calif. Alt. 4000-5000 ft. 

 Palisades ; Grand Junction ; near Boulder. 



2. LEPIDIUM L. PEPPER-GRASS. 



Style evident, at least equalling the wing-margins of the fruit. 

 None of the leaves pinnatifid. 



Blades of the basal leaves truncate and 3-toothed at the apex. 



i. L. spatulatum. 



Blades of the basal leaves acute, serrate or crenate. 2. L. crenatum. 



Basal leaves at least pinnatifid. 



Segments of the basal leaves short obovate or broadly oblanceolate in outline. 



3. L. montanum. 

 Segments of the basal leaves elongated, linear, oblong or lanceolate. 



Only the lowest leaves pinnatifid ; pod broadly oval ; style scarcely longer 



than the width of the wing-margin. 4. L. alyssoides. 



Lower stem-leaves also pinnatifid ; pod narrower, acutish at both ends ; style 



about twice as long as the wing-margin. 

 Plant low, 3 dm. high or less ; leaves or their lobes narrowly linear. 



5. L. Jonesii. 

 Plant tall, 4-8 dm. high ; upper leaves broadly linear or oblong. 



6. L. Eastwoodiae. 

 Style obsolete, at least much shorter than the wing-margin of the fruit, or stigma 



subsessile. 

 Petals conspicuous, at least equalling the sepals, spatulate or obovate. 



Blades of the petals broadly obovate, much exceeding the sepals ; style short. 



7. L. idahoense. 

 Blades of the petals spatulate ; style none. 



Cotyledons accumbent; petals broadly spatulate. 8. L. virginicum. 



Cotyledons incumbent ; petals narrowly spatulate. 



Stem glabrous or nearly so ; petals well exceeding the sepal. 



9. L. medium. 

 Stem glandular puberulent ; petals about equalling the sepal. 



10. L. ramosum. 



