12 



BRASSICACEAE 



Thlaspi — Penny Cress 



«3r, thlaspi, cress, the seeds of which were crushed [thlao]) 

 PI. 4, fig. B 

 Leaves undivided ; pod broadly winged Th. arven.se 



Lepidium — Peppergrass 



(Gr. lepidiou, little scale, referring to the pods) 

 PI. 4, fig. C 

 Leaves deeply cut ; petals lacking L. apetalum 



Bursa — Shepherd's Purse 



(L. bursa, purse, referring to the pod) 

 PI. 4, fig. D 

 Leaves deeply cut, often entire on the stem ; flowers white 



Iodanthus — Purple Rocket 



(Gr. ion, violet, anthos, flower, referring to 

 PI. 4, fig. E 

 Leaves mostly dentate ; flowers purplish, petals with a long claw 



Brassica — Mustard 



(Latin name of the cabbage) 

 PI. 3, fig. G : 1, 2 and H 



1. Upper leaves clasping 



a. Leaves smooth, glaucous, not eared at base 



b. Leaves hairy, eared at base 



2. Upper leaves not clasping 



a. Beak of pod sword-like; pods much constricted between seeds 



b. Beak round ; pods not constricted between seeds 



(1) Pods 2.5-5 cm. long; beak 6-15 mm. long 



(2) Pods 1-1.5 cm. long; beak 2-10 mm. long 

 (a) Beak 2-4 mm. long 



B. bursa-pastdris 

 the color) 



/. pinnatiUdus 



(b) Beak 8-10 mm. long 



1. Pods spreading 



2. Pods erect, appressed 



B. olerdcea 

 B. campestris 



B. alba 



B. jtincea 



B. nigra 

 B. arvensis 



Barbarea — Yellow Rocket 



(Named for Saint Barbara) 

 PL 4, fig. F 



B. barbarea 

 B. stricta 



Draba — Whitlow-grass 



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

 PI. 3, fig. I : 1, 2 

 1. Flowers white; stem leafy at base only 

 2 Flowers yellow ; stem leafy 



Roripa — Water-cress 



(Meaning of name unknown) 



PI. 4, fig. G 

 Leaves pinnate, of 3-9 leaflets ; flowers white 



Cardamine — Bitter Cress 



(Gr. kardamine, a cresslike herb) 

 PI. 4, fig. H 

 stem leaves oblong ; flowers white 



Arabis — Rock Cress 



(Referring to Arabia) 

 PI. 4, fig. I 



Basal leaves oval : 



D. carolinidna 

 D. nemorosa 



R. nasturtium 



C. bnlbdsa 



Pods ascending or erect 



a. Basal leaves pinnatifid 



b. Basal leaves mostly dentate 

 (1) Pods ascending 



(a) Seeds wing-margined 



(b) Seeds not wing-margined 

 (2) Pods erect, appressed 



Pods spreading, recurved 



A. lyrdta 



A. brachyedrpa 

 A. deutdta 

 A. hirsuta 

 A. levigata 



