192 CRUCIFERAB. 



of the shorter stamens toothed at lose. — Naturalized at 5Treka, Butler; said 

 to be adventive in the Bay region. 



18. LEPIDIUM L. Peppee-grass. 

 Ours low annuals (one perennial) with toothed or pinnatifid leaves and very 

 small flowers (1 line long or less). Petals white or none. Stamens 6, 4 

 or 2. Pod a round, ovate, or broadly oblong silicle, strongly obcompressed, and 

 in ours notched or lobed at the more or less winged apex; valves acutely carin- 

 ate, the cells 1-seeded. Style not persistent in fruit. Cotyledons incumbent. 

 (Greek lepidion, a little scale, in reference to the flattened pods.) 



Silicle notched at apex, not reticulated or only faintly. 

 Petals present; erect plants. 



Leaves toothed; pedicels terete 1. L. medium. 



Lower leaves pinnatifid; pedicels flattened 2. L. nitidum. 



Petals none; plants diffuse or prostrate; leaves pinnatifid 3. L. bipinnatifidum. 



Silicle winged at apex with two lobes or teeth and 



Conspicuously reticulated; dwarfs with mostly prostrate or decumbent stems; wings or 

 teeth approximate or parallel and 



Nearly as long as the body 4. L. latipcs. 



Very short 5. L. dictyotum. 



With finer reticulations; teeth divergent. 



Pedicels erect or ascending, shorter than the silicles; teeth very prominent; sinus 



triangular 6. L. strictum. 



Pedicels spreading or retrocurved, longer than the silicles; sinus broad and rounded. . . 



7. L. oxycarpum. 

 L. draba L. Hoary Cress. Perennial, with grayish herbage; stems several 

 from the ground, 1 ft. high, leafy below and branching at summit so as to 

 form a panicle of racemes; leaves large, ovate, sagittate-clasping at base and 

 with scattered minute teeth on the margin; pod somewhat cordate, neither 

 notched nor winged. — Garden plant, occasional as an escape in the Bay region; 

 Menlo. Thoroughly naturalized and filling fields at Yreka, Geo. D. Butler. 



1. L. medium Greene. Tall Pepper-grass. Stem erect, 1 to 2 ft. high, 

 simple below, paniculatcly branching above and bearing numerous racemes 2 

 to 3 or even 6 in. long; herbage ostensibly glabrous; leaves oblanceolate (the 

 radical oblong), narrowed at base to a petiole, sharply serrate, 2 to 3 in. long; 

 rameal leaves linear, serrate only towards the apex, shorter; petals white; 

 silicles round, l 1 /^ lines long, nearly as broad, notched at the very narrowly 

 winged apex; pedicels 2 lines long, widely (or even horizontally) spreading. 



Common in Scott Valley, Lake Co., and southward to Napa Valley. Widely 

 distributed in the western U. S. 



2. L. nitidum Nutt. Common Pepper-grass. Tongue-grass. Branching 

 from or near the base, 1 to 6 (or 10) in. high, the branches mostly simple; 

 herbage glabrous; leaves 4 in. long or less, the upper almost or quite entire, the 

 lower pinnatifid with the rachis lignlate and bearing remote entire or laciniately 

 toothed lobes; petals white, less than 1 line long, obovate, with no distinct 

 • law; stamens 6, but the 2 shorter mere rudiments; silicles round, with a nar- 

 row margin, abruptly notched at apex, 1% to 2 lines long, plane on the upper 

 face, convex on the lower, often dark purple, glabrous and shining. 



Common everywhere on the California plains, low hills and in the valleys. 

 North to Washington. Feb.-Apr. 



3. L. bipinnatifidum Desv. Wayside Pepper-grass. Stems 3 to 6 in. 

 Ion;;, freely branching from the base, diffuse or even prostrate, the plants often 

 closely matting the ground; herbage lighl green, puberulent or glabrate; leaves 

 pinnatifid or the lowest bipiunat [fid ; racemes numerous, dense and rather 

 narrow; petals none; silicles round, nearly iy 3 lines long, glabrous, faintly 



