16 MUSTARD ORDER 



BRASSICACEAE MUSTARD FAMILY 

 Sepals 4, petals 4, rarely none, separate, usually with a claw, stamens 

 usually 6, 2 shorter, rarely 1-4, ovary 2-celled, style 1, stigma entire or 2- 

 lobed, fruit a pod, usually 2-celled and many-seeded; flowers in racemes or 

 corymbs ; herbs with alternate simple, rarely compound leaves. 

 I. Pod round, globose or triangular to short-oblong 



1. Pods flattened 



a. Pods of 2 round halves, resembling spectacles Dithyrea 



b. Pods round to ovoid or oblong 



( 1 ) Seeds single in each half ; pods round to 



short-oblong Lepidium 



(2) Seeds 2-many in each half 



(a) Pods round, winged or margined 



x. Pods winged all around; flowers white 



or purplish Thlaspi 



y. Pods margined above ; flowers yellow- 

 ish Alyssum 



(b) Pods ovoid to elliptic or oblong, not 



winged 

 x. Leaves pinnatifid ; seeds several in each 

 cell 

 (x) Flowers 1-2 mm. wide; pods 3-4 Hutchinsia 



mm. long 

 (y) Flowers 5-8 mm. wide; pods 6-12 



mm. long Smelowskia 



y. Leaves entire or toothed ; seeds many in 



each cell Draba 



c. Pods triangular, not winged ; leaves pinnatifid Bursa 



2. Pods round in section or inflated, not flattened 



a. Submerged aquatic ; leaves awl-shaped Subularia 



b. Terrestrial 



(1) Pods of 2 inflated cells Physaria 



(2) Pods globose to pear-shaped or oblong, not 



inflated 



(a) Leaves pinnatifid Roripa 



(b) Leaves entire 



x. Leaves gray with star-shaped hairs ; 



pods globose to oblong Lesquerella 



y. Leaves green, not stellate-hairy ; pods Camelina 



pear-shaped 



