GENUS 17. 



MUSTARD FAMILY. 



2. Lepidium Draba L. Hoary Cress. 

 Fig. 2038. 



Lepidium Draba L. Sp. PI. 645. 1753. 



Perennial, erect or ascending, io'-i8' high, 

 hoary-pubescent, branched at the inflorescence, 

 leaves oblong or lanceolate-oblong, obtuse, 

 slightly dentate or entire, ii'-2' long, the lower 

 petioled, the upper sessile and clasping; pedicels 

 slender, ascending or spreading, 3" -6" long in 

 fruit; flowers white, about i"-2," broad; pods 

 very broadly ovate, or cordate, li" long, 2" broad, 

 arranged in short corymbose racemes; valves dis- 

 tinct, papillose, keeled, wingless, tipped with a 

 slender style \"-\" long. 



Waste grounds, Astoria and Syracuse, N. Y., Wash- 

 ington, D. C., and on ballast about the seaports. 

 Also from Colorado and Wyoming to California and 

 British Columbia. Fugitive from Europe. Native 

 also of Asia. April-June. 



3. Lepidium ruderale L. Roadside or 

 Narrow-leaved Pepper-grass. Fig. 2039. 



Lepidium ruderale L. Sp. PI. 645. 1753. 



Annual, erect, 6'-i5' high, glabrous, wiry, freely 

 branching. Basal and lower leaves oblong in 

 outline, i'-4' long, i-2-pinnatifid into linear or 

 oblong obtuse segments ; upper leaves smaller, 

 entire or with a few lobes ; flowers \" broad or 

 less, greenish; petals none; stamens 2; pods flat, 

 not margined, about i" in length, short-oval; 

 pedicels spreading or somewhat ascending, very 

 slender, ii"-2" long in fruit; valves sharply 

 keeled, barely winged; seeds marginless; coty- 

 ledons incumbent. 



In waste places, on ballast and along roadsides 

 about the cities, Nova Scotia to Texas, and recorded 

 from Bermuda. Naturalized from Europe. Has the 

 unpleasant odor of wart-cress. Occurs also in Aus- 

 tralia. Summer. 



4. Lepidium virginicum L. Wild Pepper- 

 grass. Fig. 2040. 



Lepidium virginicum L. Sp. PI. 645. 1753. 



Basal leaves obovate or spatulate in outline, 

 generally with a large terminal lobe and numerous 

 small lateral ones, all dentate, glabrous or slightly 

 pubescent; stem-leaves lanceolate or oblong- 

 linear, sharply dentate or entire, sessile, or the 

 lower stalked; flowers V'-i" broad, white, petals 

 generally present, sometimes wanting in the later 

 flowers; stamens 2; pedicels very slender, spread- 

 ing, 2"-3" long in fruit; pod flat, short-oval or 

 orbicular, minutely winged above ; cotyledons ac- 

 cumbent. 



In fields and along roadsides, Quebec to Minne- 

 sota. Colorado, Florida, Texas and Mexico. Also in 

 the West Indies, and introduced as a weed into south- 

 ern Europe. Bird's-pepper. Tongue-grass. May- 

 No v. 



