456 



WEED FLORA OF IOWA 



LINACEAE, FLAX FAMILY. 



Common Flax (Linum usitatissimum L.). 



Seeds ovate, flattened, one-fifth in. long, one-tenth in. wide, basal 

 end curved on one side; color brown, margins with whitish luster, 



Figure 315A Figure 315B 



Fig. 315. Common Flax (Linum usitatissimum). A, seed. B, cross section 



of seed. 

 (A, drawing by Ada Hayden ; B, after Winton. ) 



smooth, shining; scar on one side, near lower end, small, incon- 

 spicuous; embryo, large, straight. 



OXALIDACEAE, SORREL FAMILY. 



Lady's Sorrel (Oxalis corniculata L.). 



Pod prismatic, cylindrical, seeds 1 mm. in length ; shape and 

 markings similar to preceding. 



Oxalis (Oxalis stricta L.). 



Pod angled, awl-shaped ; seeds 1 mm. in length, elliptical, pointed 

 at one end ; surface marked by broken transverse lines of white ; 

 seed longitudinally ribbed, slightly flattened. 



