VARIOUS FARM PRODUCTS 533 



Prickly lettuce (Lactuca scariola). Dagger cocklebur (Xanthium spinosum.) 



Bracted Plantain (Plantago aristata). Chondrilla (Chondrilla juncea). 



Horse nettle (Solarium carolinense). Wild carrot (Daucus carota). 



Buffalo bur (Solanum rostratum). Wild oat (Avena fatua). 



Spiny amaranth (Amaranthus spinosus). False flax (Camelina sativa). 



Prickly Lettuce. A single average plant has been estimated to 

 bear more than 8,000 seeds. The principal leaves on the stem have 

 the unusual habit of twisting so that the upper part of the blade 

 becomes vertical. They also point north and south, hence the 

 name compass plant. The white, milky juice has suggested the 

 name milk thistle. Both of these names are incorrectly used in this 

 connection, as they are properly applied to very different plants. 

 Unlike most annual weeds, the prickly lettuce is very troublesome 

 in meadows and permanent pastures. Clover intended for a seed 

 crop is often entirely ruined. Oats and other spring grain crops 

 suffer more or less damage. When it is mixed with grain its milky 

 juice is very troublesome in thrashing. Sheep and sometimes cattle 

 will eat the young prickly lettuce, and in some localities their ser- 

 vices have been found very effective in keeping it down, especially 

 in recently cleared land where thorough cultivation is impossible. 

 Repeatedly mowing the plants as they first begin to blossom will 

 prevent seeding ana eventually subdue them. Thorough cultivation 

 with a hoed crop, by means of which the seed in the soil may be 

 induced to germinate, will be found most effective. Under no cir- 

 cumstances should the mature seed-bearing plants be plowed under, 

 as that would only fill the soil with seeds ouried at different depths 

 to be brought under conditions favorable for germination at inter- 

 vals for several years. Mature plants should be mowed and burned. 

 As the seed may be carried a long distance by the wind the plants 

 must be cleared out of fence rows, waste land, and roadsides. 



Bracted Plantain. Although generally reported as new, this 

 plant has doubtless existed before in small quantity and with less 

 robust habit in many places. In some instances, however, it is 

 known to have been introduced during recent years in lawn grass 

 seed. Its seeds are known to seedsmen as western buckhorn or west- 

 ern ripple. 



The bracted plantain is an annual, sometimes a winter annual, 

 and in some cases the roots are apparently perennial. The leaves 

 are not killed even by severe frosts. It is closely related to the 

 lance-leaved plantain, or rib grass, and to the woolly plantain. The 

 seed-bearing stems, 5 to 12 inches in height and numbering 5 to 25 

 on each plant, as in other plantains, are leafless and naked near the 

 base. Each flower produces two seeds in an egg-shaped capsule 

 which opens transversely, the dome-shaped lid with the persistent, 

 papery corolla lobes falling away with the two seeds hanging in it. 

 This kind of parachute enables the seeds to be carried a short dis- 

 tance by the wind. They usually fall near the parent plant, hence 

 after the first introduction the bracted plantain grows in dense 

 colonies, covering the ground so thickly as to choke out all other 

 vegetation. An average plant produces about 15 flower spikes, and 

 an average spike bears about 100 flowers or 200 seeds, making a 



