THE MORNING-GLORY FAMILY, CONVOLVULACE^E. 



The plants of this family possess marked characteristics by which they 

 are easily recognized : i. e., the twining stems, the trumpet-shaped flowers, 

 and the globose cartilaginous capsules with distinct divisions. There are 

 three species of Morning-glory, including among those plants which are 

 classed as weeds, the notorious Field Bindweed, the Hedge or Great Bind- 

 weed, Convolvulus sepiuni, L., var. americanus, Sims, which sometimes gives 

 trouble for a year or two after land is broken in the Prairie Provinces, and 

 the Upright Bindweed, Convolvulus spithamceus, L., which occasionally is 

 complained of in sandy land. 



Closely allied to the Morning-glories are the Dodders, belonging to a 

 small natural order, the Cuscutacece. These are curious leafless parasites 

 occurring as loose tangled masses of fleshy threads, with clusters of flowers 

 or small round pods at short interval's, attached to various plants, from 

 which they draw their nourishment. The abundant occurrence of Dodder 

 seeds among Alfalfa and Clover seeds offered for sale during recent years, 

 as well as the presence of the parasite in large quantity in some fields of 

 Alfalfa in Ontario, has given rise to much interest in these plants. The 

 Dodder, the seeds of which are most frequently found as impurities with 

 those of Alfalfa and Clovers, is the Alfalfa Dodder, Cuscuta epiihymum, 

 Murr., formerly known as Cuscuta trifolii, Bab., because it so often infested 

 Clover (Trifolium). These seeds [Plate 54, fig. 34 twice natural size and en- 

 larged 8 times] are small yellow or brown bodies varying in diameter from 

 yij to jV of an inch, irregularly globose, and more or less angled on the 

 inner scar-bearing side; the surface is granular-roughened, and these seeds 

 are very apt to be overlooked from their lack of distinct characters. When 

 soaked, the embryo is seen to be a spirally coiled worm-like body without 

 any seed-leaves. 



Mr. G. H. Clark, the Seed Commissioner of the Department of Agri- 

 culture, who has taken much trouble to investigate the origin of the Dodder 

 seeds found in Canadian commercial seeds, has detected the seeds of another 

 species in South American seeds, which he has identified as Cuscuta race- 

 mosa, 'Mart., var. chiliana, Eng. These seeds are about twice as large as 

 those of Alfalfa Dodder and have a more rounded contour and a much 

 larger and more distinct flat basal scar. These large seeds are, owing to 

 their size, much more difficult to clean out of clover seeds than the com- 

 mon variety, and should be watched for carefully in clover and alfalfa seed. 



