468 BRASSICACEAE 



ing, 3-4 mm. long : sepals oblong, about 1 mm. long, obtuse : petals white, spatulate, slightly 



longer than the sepals : silicles suborbicular or oval-orbicular, 3-4 mm. broad, margined 



above, notched at the apex. 



In all situations, Quebec to Minnesota, Kansas, Florida, Texas and Mexico. Natiu-alized in 

 Europe. Spring and fall. 



2. Lepidium medium Greene. Annual, glabrous or nearly so. Stems 1-5 dm. tall, 

 simple, or more or less branched : basal leaves 2-8 cm. long : blades coarsely toothed or 

 rarely 1-2-pinnatifid : stem-leaves narrow, more or less distinctly toothed or those of the 

 branches entire : pedicels ascending, finally 2-3 mm. long : petals conspicuous, bright 

 white : pods suborbicular, about 3 mm. broad, notched at the apex. 



In dry soil, Idaho to Vancouver Island, Texas and California. Spring and summer. 



3. Lepidium ap^talum Willd. Annual or perhaps more persistent, glabrous or puber- 



ulent, odorless. Stems 2-7 dm. tall, more or less branched : basal leaves and sometimes 



the lower stem-leaves with pinnatifid blades : upper stem-leaves narrow, incised to entire, 



erect or ascending : pedicels erect or nearly so during anthesis, thereafter becoming 2-3 



mm. long, curving out making the fruiting raceme much thicker than the top : petals 



minute and inconspicuous or obsolete : pods suborbicular, about 2 mm. broad, notched at 



the apex. 



In dry soil and waste places, Maine to the Northwest Territory, California, New York and Texas. 

 Spring to fall. 



4. Lepidium austrinumi Small. Annual or biennial, finely hirsute all over, at least 

 during anthesis. Stems 1-3 dm. tall, branched above and sometimes also at the base : 

 basal leaves spatulate. early deciduous : stem-leaves with spatulate or oblanceolate blades 

 1.5-5 cm. long : pedicels ascending during anthesis, spreading at maturity, becoming 2-3 

 mm. long : petals minute or wanting : pods suborbicular, 2 mm. broad or slightly more, 

 finely hirsute. 



In plains and prairies, Texas. Spring. 



5. Lepidium oblongum Small. Annual or biennial, minutely pubescent. Stems 

 usually much branched at the base, the branches radially spreading, more or less decum- 

 bent, 0.5-2 dm. long, usually branched : leaves rather numerous ; blades pinnatifid, 1-2 

 cm. long, the segments mostly 5-7, quite narrow, acute : pedicels puberulent : petals want- 

 ing or obsolete : pods oblong or oval, about 3 mm. long, slightly winged at the apex. 



In dry ground, near Sapulpa, Indian Territory. Spring and summer. 



4. SYNTHLl'PSIS A. Gray. 



Annual caulescent herbs, with grayish pubescent foliage. Leaves alternate : blades 

 sinuate or pinnatifid, sometimes petioled. Flowers perfect, in loose racemes. Sepals 

 oblong, spreading during anthesis. Petals surpassing the sepals, with flat blades and short 

 claws. Stamens 6 : filaments unappendaged. Ovary 2-celled : style slender : stigma entire. 

 Ovules several. Pods relatively short, strongly compressed, on ascending or reflexed 

 pedicels, the valves merely keeled. Seeds neither winged nor margined, about 10 in each 

 cavity. Cotyledons accumbent. 



1. Synthlipsis Berlandi^ri A. Gray. Foliage finely stellate-tomentose. Stems 

 branched at the base, the branches spreading, sim^^le or branched : basal leaves 3-8 cm. 

 long, with short petioles and pinnatifid blades ; stem-leaves sessile, oblong, oblanceolate or 

 oval, dentate or sinuate-pinnatifid, 1-2.5 cm. long, acute: pedicels finally recurved, 1-1.5 

 cm. long : sepals oblong-lanceolate, 3 mm. long : petals yellow to purple, about twice as 

 long as the sepals : pods suborbicular, about 6 or 7 mm. broad, reticulated, glabrous, usually 

 deflexed. 



On plains and prairies, southern Texas. Spring.— The variety with hirsute stems is S. Berlandieri 

 Mspida S. Wats. Spring. 



5. LESQUERELLA S. Wats. 



Annual or perennial scapose or caulescent herbs, -with stellate pubescence. Leaves 

 alternate, sometimes mainly basal : blades entire or undulate. Flowers perfect, in racemes 

 or panicles. Sepals 4, equal, or 2 saccate at the base. Corolla usually yellow or yellow- 

 ish, the 4 petals surpassing the sepals, entire. Stamens 6. Ovary sessile or stalked : style 

 slender : stigma capitate or 2-lobed. Ovules few. Silicles oblong or globose, inflated, the 

 valves nerveless : septum nerved from the apex to the middle. Seeds flattened, sometimes 

 narrow-margined. Cotyledons accumbent. BLADDER-roi). 



