SPERMATOPHYTA CRUCIFERAE 



487 



Pod short. 



Pod many or few seeded; obcordate-triangular. 



Pod many seeded, obcordate-triangular 4 Capsella 



Pod few seeded, orbicular, obovate or obcordate 7 Thlaspi 



Pod 2-seeded, flat, notched 6 Lepidium 



1. Sisymbrum (Tourn.) L. 



Annual or biennial herbs with usually simple spreading pubescent, hairs 

 occasionally forked or stellate; leaves entire, oblanceolate, divided, pinnatifid, 

 or runcinate; flowers in racemes; calyx open, greenish, of 4 sepals; corolla 

 white, yellow or yellowish, or rarely pink, small; pistils terete, flattish or 4-6- 

 sided; small entire stigma; seeds small oblong; cotyledons incumbent. 



A small genus of 60 species. Found in temperate regions of both hemis- 

 pheres. Several species are well known troublesome weeds. 



Sisymbrium officinal e Scop. Common Hedge Mustard 



A slender erect annual or winter annual, l^-2j^ feet high; lower leaves 

 divided, runcinate, pinnatifid, upper entire or hastate at base; flowers small, 

 yellow, borne in spike-like racemes; seeds small, brown; cotyledons incumbent. 



Fig. 255. Tumbling Mustard (Sisymbrium altissimum). 

 Common in Canada and from Minnesota to Washington. 

 (Dewey, U. S. Dept. Agrl.) 



