CRUCIFERfla. 25 



23. LEPIDITJM, Linnaeus. 



1. Iu latipes, Hook. Stout, rigid stem, 1 to 3 in. long; leaves longer: pods long- winged, 



2. L. dictyotum, Gr. var. acutidens Gr. Stem slender, 1 to 3 in, high. 



3. L. oxycarpum, T. & G. Slender: petals none: stamens 2: smooth pods nodding. 



4. I*, nitidum, Nutt. Petals small: pods shining, acutely margined. 



5. L. etrictum. Often matted: sepals persistent: pods erect in dense racemes. 



6. L. Menziesii, DC. Hispid or pubescent: petals none: pods glabrous. 



7. I*, lasiocarpum, Nutt. Rough-pubescent: pods hispid on margin. 



8. L. Virginicum, L. Smooth stem erect, at length leafless below, paniculate. 



9. L. Draba, L. Perennial: leaves not lobed: petals large: pods cordate. 



10. Xi. campestre, L. Stout : leaves serrate: pods ovate, broadly winged, scabrous. 



24. SENEBIERA, Do Candolle. 

 1. S. didyma, Pers. Racemes opposite pinnatifid leaves. Ill-scented. 



25. HETERODRABA, E. L. Greene. 

 I. H. unilateral la, Greene. Branching, nearly prostrate; pedicels reflexed. 



26. ATHYSANUS, E. L. Greene. 



1. A, pusillus, Greene. Very slender (Thysanocarpua pusillu^ Hooker> 



27. THYSANOCARPUS, Hooker. 



1. T. curvipes, Hook. Leaves clasping: border of pods often perforate. 



2. T. laciniatus, Nutt. More slender: leaves scarcely clasping: pods entire. 



3. T. radians, Benth. Glabrous: pods with radiating ribs, 4 or 5 lines broad. 



28. RAPHANUS, Linnaeus. 



1. R. sativus, L. Petals veiny, color variable: pithy pods 1 to 1^ in. long. 



2. R, Raphanistmm, L. Similar: pods more constricted between seeds. 



CAPPARIDACE^E. 



1. ISOMERIS, Nuttall. 



L X. arborea, Nutt. Yellow flowers in bracteate racemes: stamens exserted. 



2. CItEOME, Linnaeus. 



1 C. platycarpa, Torr. Erect annual: yellow flowers corymbose; pod hanging. 



