MUSTARD FAMILY IO3 



white or flesh-colored flower. Corolla flattened, T A or % in. 

 long; tips of outer petals becoming recurved, ^ m - l° n S or 

 slightly more. — Yosemite Valley, Snow Creek, Mt. Lyell 

 (10,500 ft.), Tilden Lake, Macomber Ridge; seldom seen in 

 flower and often overlooked. D. pauciflora Wats, is a similar 

 species which may occur. It has coral-like roots and nodding 

 flowers nearly 1 in. long. 



CRUCIFERAE. Mustard Family. 

 Herbs with alternate or basal leaves, no stipules, and the 

 flowers in terminal bractless racemes. Sepals and petals each 

 4 (except Lepidium), regular and distinct. Petals narrowed 

 below to claws, the blades spreading in the form of a cross. 

 Stamens 6. Ovary superior, with a single style and stigma, 

 developing into a 2-celled pod which opens from below up- 

 ward, leaving the thin partition behind, or permanently closed. 

 Herbage with mustard-like taste, never poisonous. 



A. Leaves entire or merely toothed (even the lower). 



Pods l /2 in. or less long. 



Pedicels erect or spreading; seeds several; pods 

 opening at maturity. 



Pods oblong or lanceolate 1. Draba. 



Pods nearly orbicular, flat, notched at summit 4. Lepidium. 



Pods thick, pear-shaped or nearly globose; water 



plants 5. Subularia. 



Pods wedge-shaped, flat, notched at summit 6. Capsella. 



Pedicels recurved; seeds 1 or 2 in the orbicular pod. 



Pods not wing-margined, minutely bristly 2. Athysanus. 



Pods broadly wing-margined 3. Thysanocarpus. 



Pods 1 in. or more long, slender. 



Flowers orange or yellow, }i in. or more across 10. Erysimum. 



Flowers white or purplish, smaller. 



Upper leaves oblong or narrower 14. Arabis. 



Upper leaves nearly orbicular 15. Streptanthus. 



B. Leaves with several or many lobes (especially the lower). 



Herbage finely pubescent (except in one introduced 



Brassica) ; plants of dry places. 



Pods 1-celled or with spongy cross-partitions 7. Raphanus. 



Pods 2-celled, wedge-shaped, notched at summit 6. Capsella. 



Pods 2-celled, linear, beaked at summit. 



Leaves entire or with large lobes 8. Brassica. 



Leaves finely cut into many small lobes 9. Sisymbrium. 



Herbage glabrous or nearly so; succulent plants of 



moist places. 

 Pods cylindric or 4-sided. 



Seeds in 2 rows in each cell 11. Radicula. 



Seeds in 1 row in each cell 12. Barbarea. 



Pods flattened parallel to the partition 13. Cardamine. 



