374 



Missouri Agricultural Report. 



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(o); (fig. 20) peppergrass (b), cinquefoil (d), spurge (1), spiny sida (m); 

 (fig. 21) bracted plantain (e). Seeds of Canada thistle (fig. 18, r) or of small- 

 fruited false flax (fig. 17, q), if found in abundance, indicate that the source of 

 the seed is Canadian. 



European origin of red clover seed is indicated by the presence of certain 

 weed seeds, and the occurrence of several kinds of these in the same sample 

 (especially in the absence of the kinds heretofore mentioned as occurring in 

 American-grown seed), lends weight to the 'probability of European origin, 

 as follows: (Fig. 18) clover dodder (g), wild chicory (t; (fig. 19) wild 

 spurry (p), chickweed (q), forked catchfly (t) ; (fig. 20) bird's-foot trefoil (g), 

 wild geraniums (h, i and j), red pimpernel (o), forget-me-not (q), vervain (r) ; 

 (fig. 21) field madder (g), wild corn salad (i and j), scentless camomile (o), 

 oxtongue (r), hawkweed picris (s). The presence of a considerable quantity of 

 distinctly small-seeded red clover seed further indicates European origin. 



TESTING ALSIKE CLOVER SEED. 



Alsike clover seed is distin^iished from otlier kinds by its dark- 

 green color, the small size, and the heart-shaped oval form of individual 



seeds. The lighter colored seeds 

 ' ' ' are often mottled (fig. 24.) Old 



seed is distinguished from new by 

 the dull, reddish-brown color it 

 acquires. 



White clover seed often ap- 

 pearing in alsike seed is distin- 

 guished by its yellowish or pinkish 

 color. 



Yellow trefoil seed, some- 

 times used as an adulterant and 

 often present as an incidental im- 

 purity, is coarser than the alsike 

 seed and is further distinguish- 

 able by its greenish-yellow or brown color and the characteristic form 

 of individual seeds (figs 23 and 24). Adulterants used other than trefoil 

 seed are old alsike seed, timothy seed and weedy screenings (fig. 8). 



Germination proceeds between the second and sixth days of the test, 

 and the viability often attains 99 per cent. Hard seed is less frequently 

 observed in alsike seed than in red clover. The purity commonly amounts 

 to 98 or 99 per cent. 



The noxious weed seeds occurring in alsike clover seed include: (Fig. 17) 

 dock (f), white campion (j), bladder campion (k), night-flowering catchfly (1), 

 pennycress (n), field peppergrass (o), small-fruited false flax (q), English char- 

 lock (t); (fig. 18) tumbling mustard (c), clover dodder (g) very rarely, rat-tail 

 plantain (1), buckhorn (m), ragweed (n), o.xeye daisy (q), and frequently Can- 

 ada thistle (r). 



Other common weed seeds in alsike seed include: (Fig 19) witch-grass 



:'r\\\^- 



Fig. 



24. — Seeds of alsike clover: a, 

 Seeds showing' variation in form 

 and surface appearance, enlarged ; 

 b, natural size of seeds. 



