VOL. II.] 



MUSTARD FAMILY. 



2. Sophia pinnata (Walt.) Britton. Tansy- 

 Mustard. (Fig. 1767.) 



Erysimum pinnatum Walt. Fl. Car. 174. 1788. 

 .Sisymbrium canescens Nutt. Gen. 2: 68. 1818. 

 Descurainia pinnata Britton, Mem. Torr. Club, 5: 173. 1894. 



Densely canescent nearly all over, pale; stem erect, 

 branched, 8 / -24 / tall, slender, the branches ascending. 

 Leaves 2 / ~4 / long, oblong in outline, 2-pinnatifid into 

 very numerous small toothed or entire obtuse segments; 

 pedicels very slender, spreading nearly or quite at right 

 angles to the axis, 5 // -7 // long, usually longer than the 

 pods; flowers i // -i^ // broad; pods horizontal or ascend- 

 ing, oblong or linear-oblong, compressed, 3 // -4 // long, i" 

 wide, glabrous or somewhat canescent; style minute; 

 seeds plainly in 2 rows in each cell. 



In dry soil, Virginia to Florida and Texas. The western 

 plants, commonly referred to this species, are here considered 

 to belong mostly to the next. May-July. 



3. Sophia incisa (Engelm.) Greene. 

 Western Tansy-Mustard. (Fig. 1768.) 



Sisymbrium brachycarpon Richards. Frank. Journ. 



744. 1823 ? 

 Sisymbrium incisum Engelm.; A. Gray, Mem. Am. 



Acad. 4: 8. 1849. 

 Descurainia. incisa Britton, Mem. Torr. Club, 5: 173. 



1894. 

 Sophia incisa Greene, Pittonia, 3: 95. 1896. 



Resembles the preceding species, but is greener, 

 nearly glabrous, or the pubescence is mixed with 

 short glandular hairs. Leaves pinnately divided, 

 and the pinnae i-2-pinnatifid into linear-oblong 

 entire or toothed segments ; fruiting pedicels 

 widely ascending, filiform, 5 // -io // long, usually 

 longer than the pods; pods 4 // -7 // long, about \" 

 thick, somewhat swollen, erect or ascending ; 

 seeds in i or 2 rows. 



In dry soil, Minnesota to the Northwest Territory 

 and British Columbia, south to Tennessee, Kansas, 

 Texas and California. May-Aug. 



4. Sophia Hartwegiana (Fourn.) Greene. 



(Fig. 1769.) 



Sisymbrium Harlwegianum Fourn. Sisymb 66 



1865. 

 Sisymbrium incisum var. Harlwegianum Brew 



& Wats. Bot. Cal. i: 41. 1876. 

 Descurainia Hartwegiana Britton, Mem. Ton- 

 Club, 5: 173. 1894. 



Sophia Hartwegiana Greene, Pittonia, 3: 95. 1896. 

 Similar to the two preceding species, densely 

 minutely canescent or puberulent, stem i-2 

 tall, the branches slender, ascending. Leaves 

 usually less finely dissected, pinnately divided 

 into 5-7 pinnae, which are pinnatifid with ob- 

 tuse segments and lobes; fruiting pedicels 

 erect-appressed or closely ascending, \%"- 

 4" long, shorter than or equalling the pods; 

 pods erect or nearly so, linear, 4 // -5 // long 

 about l / 2 " thick; seeds in i row. 



In dry soil, Minnesota to the Northwest Territory 

 and Oregon, south to Utah, Mexico and California. 

 The northern plant may be distinct from the plant 

 of Fournier, which was Mexican. May-July. 



10 



Hartweg's Tansy- Mustard. 



