1 8 General Key to the Families 



them spurred or saccate at the base, the inner pair narrower, their 

 callous-crested tips united over the stigma; fruit a pod containing 

 one or more seeds. 



I. DicENTRA. Benth. 



1. D. formosa. DC. Wild Bleeding-heart. 



2. D, uniflora. Kell. One-Hozvercd Bleeding-heart. 

 II. CoRYDALis. (Dill.) Medic. 



I. C. aurea. Willd. Golden Corydalis. 



XXXIII. CRUCIFER^. MUSTARD FAMILY 



Herbs with pungent watery juice; leaves alternate; flowers cru- 

 ciform, tetradynamous, regular, in terminal racemes or corymbs ; 

 fruit a silique or silicic, sometimes nut-like, the pods and seeds 

 give the chief character of the genera. 



TRIBE ALYSSE^ 

 I. Draba. (Dill.) L. 



1. D. incana. L. White Whitlow Grass. 



2. D. lonchocarpa. Rydb. Long-podded Whitlow Grass. 



3. D. prsealta. Spring Whitlozv Grass. 



4. D. aurea. Vahl. Golden Whitlow Grass. 



5. D. alpina. L. Alpine Whitlow Grass. 



6. D. nivalis. Liljb. Arctic Whitlozv Grass. 



7. D. glacialis. Adams. Pale Yellow Whitlow Grass. 



TRIBE PHYSARIE.E 

 II. Physaria. Gray. 



I. P. didymocarpa. (Hook.) Gray. Bladder-pod. 



TRIBE LEPIDIE^ 



III. Thlaspi. (Tourn.) L. 



I. T. arvense. L. Penny Cress. (Introduced.) 



IV. Lepidium. (Tourn.) L. 



I. L. apetalum. Willd. Pepper Grass. 



TRIBE CAMELINE^ 

 V. Capsella. Medic. 



I. C. Bursa-pastoris. (L.) Medic. Shepherd's Purse. 

 (Introduced.) 



