CRUCIFERAE (MUSTARD FAMILY) 213 



stems usually many from the enlarged crown of the biennial (possibly peren- 

 nial) root, decumbent-spreading, 1-2 dm. long: leaves pinnatifid, sometimes 

 bipinnatifid, with short acute segments; the upper tending to become entire: 

 flowers in dense racemes: sepals oblong-oval, half as long as the white petals: 

 silique elliptic to suborbicular. Dry saline soils; Montana to New Mexico 

 and far westward. 



6. Lepidium Jonesii Rydb. Bull. Torr. Bot. Club 29: 233. 1902. Glabrous 

 biennial or sometimes perennial: stem simple below, branching freely from 

 the base upward, 2-3 dm. high: basal leaves pinnatifid with linear acute di- 

 visions; stem leaves similar but becoming linear and entire above: sepals 

 oblanceolate, obtuse, much shorter than the white petals: silique ovate, 

 emarginate; style short, enlarged upward toward the rather large circular 

 stigma. (L. brachybotryum Rydb. 1. c.) Western Colorado and in Utah. 



7. Lepidium apetalum Willd. Sp. PL 3: 439. 1801. Glabrous annual, with 

 erect stem, generally simple below and more or less paniculately branched 

 above but sometimes very freely branched throughout, 1-2 dm. high: leaves 

 usually pale green; the lower more or less incisely toothed or pinnatifid: 

 flowers apetalous: stamens only 2: raceme appearing contracted just below 

 its summit: silique orbicular, glabrous, the stigma sessile in the evident 

 notch. Very widely distributed; across the continent northward; south 

 through the Rocky Mountains to New Mexico. 



8. Lepidium divergens Osterh. Bull. Torr. Bot. Club 30: 237. 1903. Bien- 

 nial, minutely pubescent, divergently branched from the base : radical leaves 

 broadly spatulate, more or less dentate, short-petioled ; cauline smaller and 

 mostly entire: racemes long, with horizontal pedicels: petals wanting: capsule 

 elliptic, glabrous, emarginate, 3 mm. long. In the mountains; northwestern 

 Colorado. 



9. Lepidium medium Greene, Erythea 3: 36. 1895. Glabrous annual, the 

 stem simple below, usually sparingly branched upward, 2-4 dm. high: leaves 

 narrowly lanceolate, more or less toothed but scarcely pinnatifid; the upper 

 linear and entire: pedicels slender, early divaricate: petals small but evident: 

 stamens 2 or 4: silique orbicular, retuse, the stigma sessile. L. intermedium, 

 From Texas to Idaho and California. 



10. Lepidium ramosissimum A. Nels. Bull. Torr. Bot. Club 26: 124. 1899. 

 Obscurely pruinose-pubescent biennial, profusely branched; the branches 

 either divaricate and crowded the whole length of an excurrent axis, or dif- 

 fusely spreading from the base, or both: first year's leaves oblanceolate, 

 coarsely toothed; the second year's leaves cauline, oblanceolate, sparsely 

 toothed; the upper entire, linear or oblong: racemes very numerous; the 

 flowers crowded: petals minute: stamens 2 (to 4) : silique broadly ovate, nearly 

 smooth, the notch relatively broad and deep. L. virginicum. Plains of south- 

 western Wyoming and northern Colorado. 



11. Lepidium ramosum A. Nels. 1. c. 125. Obscurely granular-puberulent : 

 a simple erect stem from the rosette of the first year's leaves, corymbosely 

 branched from the base up, 1-2 dm. high: leaves much as in the preceding, 

 some of the lower cauline often pinnately lobed and rather large: racemes 

 contracted just below the summit, the pedicels spreading after flowering: 

 sepals subacute, about as long as the narrow spatulate petals: stamens 2 

 (to 4) : silique orbicular narrowly winged around the summit, the sinus deep 

 and narrow. Western Wyoming and northward and westward. 



12. Lepidium lasiocarpum Nutt. T. & G. Fl. N. A. 1: 115. 1838. Hirsutely 

 white-pubescent: the stem branching from the near base: lower leaves pin- 

 nately parted, the lobes rather broad and obtuse; the cauline spatulate, more 

 or less dentate: pedicels flattened horizontally: petals minute or none: sta- 

 mens 2: siliques orbicular, hispidulous, emarginate, with a narrow sinus. 

 Sandy soils; from southwestern Colorado to Texas and California. 



13. Lepidium pubecarpum A. Nels. Bot. Gaz. 30: 189. 1900. Annual, 

 freely branched from the base and paniculately upward, not much more than 

 1 dm. high, obscurely puberulent: leaves small, glabrous, linear or some- 

 what spatulate, acute, sometimes remotely toothed : petals wanting : the sepals 



