MUSTARD FAMILY 21 



dense corymbs or racemes ; leaves gray-hairy, wavy-toothed or lobed ; peren- 

 nial. 

 Stems erect, densely white-hairy; leaves ovate to 



lanceolate D. Wislizenii 



DRABA Linne 1753 DRABA 



(Gr. drabe, a plant of the mustard family) 



PL 5, fig. 5 ; pi. 6, fig. 18-20. 



Sepals 4, petals 4, yellow, yellowish or white, stamens 6, pod ovoid 

 to oblong or linear-oblong, flat, few-many-seeded, style usually short; flow- 

 ers in racemes or corymbs ; leaves simple, entire or toothed ; annual, biennial 

 or perennial. 



1. Annuals 



a. Flowers white 



(1) Pods in an umbel-like cluster; leaves en- 



tire D. carolinidna 



(2) Pods in a raceme; leaves usually toothed D. cunei folia 



b. Flowers yellow or white 



(1) Plant low, 5-10 cm. high, smooth; leaves 



basal D. crassifolia 



(2) Plant 10-30 cm. high, hairy; stem leafy, 



at least below D. nemorosa 



2. Perennials, as shown by the rootstock or the old 



stem or leaf bases 



a. Flowering stems leafless, tufted; flowers yel- 



low to white 



(1) Leaves ovoid to spatulate; pods oblong D.ventosa, 



(2) Leaves linear to linear oblong; pods ovoid D. oligosperma 



b. Flowering stems leafy 



(1) Flowers white D.incdna 



(2) Flowers yellow , A>^./ 



(a) Pods smooth, straight D. chrysdntha 



(b) Pods hairy, twisted 



x. Stem and leaves with long spreading 



hairs D. streptocarpa 



y. Stem and leaves gray with close hairs D.aurea 



ERYSIMUM Linne 1753 ERYSIMUM, WALLFLOWER 

 (Gr. erysimon, hedge-mustard, transferred from another plant) 



PL 5, fig. 4; pi. 6, fig. 28-29. 

 Sepals 4, petals 4, yellow, orange or purple, pod linear, 4-sided, seeds 



