84 FARM WEEDS OF CANADA ' 



teeth and an arrow-shaped base. The thick pods are broad- 

 ly ovate, boat-shaped, being rounded below and hollowed out 

 above. Each pod contains two seeds. 



The seed is 1/12 of an inch long, egg-shaped, but pointed 

 at the scar end. The surface is finely roughened and dull, with 

 a mealy appearance. Two grooves, often filled with mucilage, 

 extend from the sharp basal end almost to the other end of the 

 seed. 



SHEPHERD'S PURSE (Capsella Bnrsa-pastoris L.). 



Other Latin names: Bursa pastoris Weber; Thlaspi Bursa- 

 pastoris L. 



Introduced from Europe. Annual and winter annual. 

 Few plants are so variable in size and appearance. It may be 

 bright green and nearly smooth, or gray from very short ap- 

 pressed hairs. A Seed-bearing plant may be a dwarf, little more 

 than an inch or two high, or a vigorous, branching plant, three 

 feet high, with many pods. There may be at the base a 

 vigorous rosette of leaves, or none at all. The leaves may 

 be deeply cut, pinnatifid, or without any teeth or division. 

 The stem-leaves are for the most part arrow-shaped, with two 

 sharp, ear-like projections, one on each side of the stem. The 

 flowers are small and white. The only part of the plant which 

 seems to be constant is the seed-pod, which is flat, triangular 

 in shape, 1/4 of an inch long, wedge-shaped at the base, notched 

 at the top, with the outer angles rounded. Each pod contains 

 about 20 seeds. 



The seed (Plate 73, fig. 31) is small, 1/24 of an inch long, 

 oblong, reddish brown, the surface dull and punctured. When 

 put in water it develops a large amount of mucilage and a cover- 

 ing of rather long but very fine, transparent hairs. 



