CRUCIFERACEAE (MUSTARD FAMILY) iii 



STREPTANTHUS (Twist Flower) 



Branching. Flowers white or purple. Sepals usually colored. Stigma 

 entire. Pod sessile, compressed or subterete; valves i-veined. Seed 

 flat, margined or winged. — (Gk. streptos = twisted, anthos = a flower ; 

 referring to the twisted petals.) Not common. 



LEPIDIUM (Peppergrass) 



Leaves small, dentate to pinnatifid. Flowers white, small, in terminal 

 racemes. Petals rounded at apex, sometimes none. Stamens 2-6, free. 

 Style o-i. Pod emarginate to deeply notched at the apex. Seed not 

 winged. — (Gk. lepidion = a little scale ; from the form of the fruit.) Spe- 

 cies too diiEcult for beginners. 



CORONOPUS (Wart Cress) 



Annual or biennial, diffuse. Leaves mostly pinnatifid. Flowers smaU, 

 whitish. Stamens 2-6. Stigma sessile. Pod small, sessile ; valves oblong 

 or subglobose, obtuse at each end. — (Gk. korone = a crow, pons = foot; 

 referring to the deeply cleft leaves.) 



A. Pod notched at apex, rough-wrinkled. W. C. dldymus 



AA. Pod not notched at apex, tubercled. W. C. procumbens 



THLASPI (Pennycress) 



Low, erect, glabrous. Leaves entire or dentate; at least the upper 

 stem leaves auriculate and clasping. Flowers white or purplish. Petals 

 obovate br oblanceolate. Stamens free. Style o-i. Seed wingless. — 

 (Gk. thlaein = .to crush ; on account of the flat pod.) 



A. Pod 8-12 mm. wide, broadly wing-margined, notched' i-| its length; annual. 

 W. E. T. arvense (field pennycress) 



AA. Pod 2-s mm. wide, hardly wing-margined or notched; perennial. C. E. 



T. alpestre (perennial pennycress) 



SISYMBRIUM (Tansy Mustard) 



Annual or biennial. Stamens free. Stigma simple or 2-lobed. Pod 

 linear, terete or flat. Seeds many, in i or 2 rows in each cell, marginless. — 

 (The Greek name of some plant of this family.) 



A. Pubescence none or of simple hairs; stigma 2-lobed; pod firm. 



B. Pod appressed, awl-shaped, 1-1.5 cm. long. W. E. — A bad weed. 



S. officinale (hedge mustard) 

 BB. Pod spreading, linear, s-io cm. long. W. E. — -A bad weed. 



S. altlssimum (tumbling mustard) 

 AA. Pubescence of stellate or occasional forked hairs or reduced to minute granules; 

 stigma entire; pod delicate. 



C. Seeds in 2 rows in each celt of the pod. E. S. canescens 

 CC. Seeds in i row in each cell of the pod. 



