12 



FOOD HABITS OF THE GROSBEAKS. 



which are furnished with formidable spines. This grass is a very vile 

 weed of the southern fields and the orange groves of Florida." 



The seeds of other grasses, including 

 cockspur grass (Echinochloa crus-galli, 

 fig. 2), crab grass {Syntherisma sangui- 

 nalis), and allied species, which are 

 well-known weeds, were fed upon by 31 

 redbirds, yard grass (Eleusine indica) 

 by 31, and unidentified grasses by 22. 

 Seeds of the nearly related sedges 

 (Carex et al.) were devoured by 41 car- 

 dinals, those of vervians (Verbena 

 hastata, fig. 3, and V. urticce folia) by 

 25. Twenty-two birds ate seeds of 

 the well-known ragweeds (fig. 6), and 39 those of various spurges. 

 Among the other weed seeds eaten in smaller quantities are those 

 of dodder, a serious pest in grain crops; 

 vetch, dock, sow thistle, plantains, includ- 

 ing the detestable ribgrass (fig. 4) ; tum- 

 ble weed (fig. 18), sunflower, violets, gera- 

 niums, stargrass, spiny sida, corn grom- 

 well (fig. 5), spiderwort (PI. II, fig. 7), 



Fife. 2. — Seeds of cockspur grass 

 (Echinochloa crns-galli). (From 

 Hillmaii, Nevada Experiment 

 Station.) 



D a 



Fig. 3. — Seeds of blue vervain 

 (Verbena hastaia) . (From 

 Hillman, Nevada Experiment 

 Station.) 



lamb's-quarters, chickweed, stick-tight, 



sorrel, button weed (PL II, fig. 11), and 



stick-seed. To this list W. D. Doan adds 



clover and partridge pea. a One plant in 



the above list, namely, buttonweed, is 



known also as alligator head in the South, where it is a bad weed in 



rice fields. It has been said that " as the seeds are about the color of 



the soil they are not easily seen and are not apt to be picked up by 



birds." This is 

 a mistake, 

 however, for 

 these seeds are 

 devoured by 

 many kinds of 

 birds, and 

 some, as the 

 bobwhite, eat 

 large numbers 



(From Hillman, of them. 



After plants 



have seeded it is impossible for man appreciably to diminish the 

 number of seeds. But this work is the peculiar function of 



Fig. 4. — Seeds of ribgrass (Plantago lanceolata) 

 Nevada Experiment Station.) 



a Bull. 3, Agr. Exp. Sta., W. Va., 1888, p. 74. 



