CRUCIFERAE (MUSTARD FAMILY) 



207 



broadly obovate, usually acute : corolla cream-color or white ; the spur straight 

 and nearly twice as long as the body: capsule short-oval to oblong, obtuse, 

 reflexed on the ascending pedicels. (C. brachycarpum Rydb. Bull. Torr. Bot. 

 Club 34: 426. 1907.) Southwest Colorado to Utah. 



48. CRUCIFERAE B. Juss. MUSTARD FAMILY 



Annual, biennial, or perennial herbs, sometimes with woody base, with 

 watery acrid or pungent sap. Leaves alternate. Flowers perfect, racemose 

 or corymbose. Sepals 4, deciduous. Petals 4, or rarely wanting, alternating 

 with the sepals. Stamens 6, tetradynamous, rarely only 2 or 4; the two outer 

 shorter, opposite the inner sepals. Ovary 2-celled by a septum which stretches 

 across from the placentae, rarely 1-celled; style undivided or wanting; 

 stigma entire or 2-lobed. Fruit a capsule, often greatly elongated, techni- 

 cally called a silique* or, if short, a silicic. The two valves (in most cases) 

 fall away from the partition or septum, which persists and is often known as 

 the replum. Seeds attached to both sides of the septum. 



Silique dehiscent, i. e., the two valves separate from the septum at 



maturity. 

 Silique borne on a long stipe ........ 



Silique sessile on the receptacle, or very short-stipitate. 



Silique linear or oblong, at least three times longer than broad. 

 Mature silique long-linear (more than 2 cm.). 

 Silique flattened parallel to the septum. 



Pubescence branched or stellate ..... 



Pubescence wanting or simple ..... 



Silique terete or 4-angled, slightly flattened if at all. 

 Flowers yellow, large. 



Silique 4-angled; plant roughish-pubescent 



Silique terete; plant glabrous ..... 



Flowers not yellow; silique terete or nearly so. 

 Petals with crisped margin; stem succulent . 



Petals flat; stem not fleshy 



Mature silique short-linear or oblong (less than 2 cm.). 

 Flowers white or purple. 



Plants glabrous ........ 



Plants pubescent. 



Leaves entire or toothed 



Leaves pinnatifid ....... 



Flowers yellow. 



Leaves dissected ........ 



Leaves lyrately broad-lobed. 



Silique distinctly beaked by the persistent style 

 Silique beakless. 



Seeds in 2 rows, flat ...... 



Seeds in 1 row, globose or oblong .... 



Silique short, rarely more than twice as long as it is broad. 

 Siljque twin, each cell much inflated, subglobose 

 Silique globose or oblong, not twin. 



Scarcely flattened, nearly circular in cross section. 

 Flowers white; silique pear-shaped 



1. Stanleys. 



23. Arabis. 

 5. Streptanthus. 



24. Erysimum. 



2. Schoenocranibe. 



4. Caulanthus. 



3. Thelypodium. 



13. Cardamine. 



22. Stenophragma. 

 20. Smelowskia. 



21. Sophia. 



Flowers yellow; silique globose or ellipsoid 

 Silique flattened parallel to the septum 



Silique flattened at right angles to the narrow septum. 

 Silique triangular-obovate or obcordate. 



Radical leaves pinnatifid; silique cuneate . 

 Radical leaves entire or merely toothed 

 Silique elliptic or oval. 



Small aquatic annuals ...... 



Terrestrial plants. 



Seeds several in each cell ...... 



Seeds solitary in each cell ..... 



Silique indehiscent, i. e., the valves not separating from the septum 

 even at maturity ......... 



11. Barbarea. 



12. Roripa. 



14. Physaria. 



18. Camelina. 

 15. Lesquerella. 



19. Draba. 



17. Capsella. 

 8. Thlaspi. 



6. Subularia. 



16. Hutchinsia. 

 7. Lepidium. 



10. Raphanus. 



* For convenience the term silique has been used to designate the fruit in this family 

 no matter what its shape. 



