264 CONTEIBUTIONS PKOM THE NATIONAL HEEBARIUM. 



KEY TO THE GENERA. 



Pods indehiscent, 1-celled, with perforated wing- 

 margin 1. Thysanocarpus (p. 266). 



Pods dehiscent (except in Dithyraea and Raphanus), 

 2-celled, notwing-margiaed. 

 Pods stipitate , terete . (Anthers sometimes curved 

 or twisted.) 



Pods long-stipitate; stipes slender 2. Stanleya (p. 266). 



Pods short-stipitate ; stipes stout. 



Sepals spreading in an thesis, soon decidu- 

 ous 3. Stanleyella (p. 267). 



Sepals erect or ascending in anthesis. 



(Stigma entire or indistinctly lobed, 



the lobes exjianded over the valves . ) 



Stigma conical; outer sepals gibbous 



at the base 4. Hesperidanthus (p. 267). 



Stigma trimcate; sepals scarcely gib- 

 bous at the base. 

 Septum of pod with a strong 



midrib 5. Pleurophragma (p. 267). 



Septum of the pod without mid- 

 rib 6. Thelypodium (p. 268). 



Pods not stipitate, of various shapes. 



Anthers sagittate at the base, spirally curved. 

 Pods terete; flowers small, more or less 



irregular; calyx not urceolate 7. Heterothrix (p. 268). 



Pods flattened parallel to the jjartition; 

 flowers large, regular; calyx urceo- 

 late 8. EuKLisiA (p. 268). 



Anthers neither sagittate nor spirally curved. 

 Pods more or less flattened contrary to 

 the narrow septum. 

 Pods didymous; plants densely stel- 

 late-pubescent. 

 Seeds solitary in each cell, the 

 halves of the pod falling 

 with the contained seeds; 



pods strongly flattened 9. Dithyraea (p. 269). 



Seeds 1 or 2 in each cell, not 

 retained by the valve; 



pods inflated 10. Physaria Cp. 270). 



Podsnot didymous; plants not densely 

 stellate (except in Nerisy- 

 renia). 

 Pods oblong-linear, little com- 

 pressed ; plants strongly 



stellate-pubescent ... .11. Nerisyrenia (p. 270). 



Pods orbicular, oval, or cuneate, 

 strongly flattened; plants 

 not stellate-pubescent. 

 Cells 1-seeded ; pods broadest 

 at the base. 



