140 FARM WEEDS OF CANADA 



bearing thick, cylindrical spikes 1 to 4 inches long, with con- 

 spicuous, pointed, bracts. Capsules 2-seeded. 



The seed (Plate 75, fig. 71) is boat-shaped, of the same 

 size and form as that of Ribgrass but slightly wider, with sharper 

 edges to the margin of the inner face. The elongated scar 

 consists of 2 small, shallow pits lying close together in the centre 

 of the inner excavated face, the whole of which is whitened by 

 a coat of dried mucilage. The rounded outer face has a distinct 

 shallow groove crossing it just below the middle. This' groove 

 and the two pits of the scar are the best characteristics for 

 distinguishing this seed. 



THE MADDER or BEDSTRAW FAMILY 



(Rubiaceae) . 



This is a large family which shows great variations in habits 

 of growth and in appearance. The most important members 

 are tropical, such as the coffee. The plants are herbaceous or 

 woody, with opposite or whorled leaves, flowers bearing both 

 stamens and pistils and various fruits. 



The seeds of the following weeds are found in commercial 

 seeds : 



Field Madder (Sherardia arvensis L.). A slender, prostrate, 

 square-stemmed plant, with lance-shaped leaves in whorls of 

 4-6, and small pink or blue flowers. The seed is ash-gray from 

 fine appressed hairs, eggshaped, not quite 1/8 of an inch long, 

 crowned with 3 dry, persistent calyx teeth. 



Northern Bedstraw (Galium boreale L.), the most common 

 of the bedstraws or cleavers. A native perennial, with square 

 stem, linear, lance-shaped leaves in whorls of 4, and compact 

 panicles of bright white flowers. 



The seed (Plate 75, fig. 73) 'is a good representation of 

 the seed of the genus Galium, only it is much smaller than some 



