56 THE MONTANA EXPERIMENT STATION. 



regions; at Missoula and Helena and reported from Manhattan, 

 Livingston, Billings, Cinnabar, Great Falls and at points along 

 the railway in Silver Bow and Beaverhead counties. It is easily 

 uprooted with a hoe and should be piled into heaps and burned 

 when dry, as the smallest plants bear fruit and will serve to re- 

 stock the soil, if simply dug up and left. Mowing the plants, as 

 is frequently done, is of little aid toward their extermination, as 

 the stubs remaining will bear enough fruit to replant the soil for 

 the ensuing season. It is better adapted to the conditions existing 

 in the Milk River and Yellowstone Valleys than elsewhere in the 

 state and may there prove a serious menace to the agricultural 

 interests, but should be exterminated wmerever found, as the law 

 requires. Seeds distributed principally by the railways, irrigation 

 ditches and mud of passage. [Fig. 15 a and b.] 



109. SAPONARIA VACCARIA, L. Cockle; Cow Cockle. 



A smooth European annual, one or two feet high; with opposite, 

 clasping leaves and conspicuous pink flowers terminating the level- 

 topped spread of branches. A common and pernicious weed in 

 grain fields in the eastern part of the state, but rare westward. 

 It should not be allowed to' secure a footing in regions not yet in- 

 fected and may be hand-pulled where the plants are few or its dis- 

 tribution limited. Usually introduced and spread in the grain 

 seed and, apparently, by irrigation. [Fig. 16.] 



110. *SENECIO VULGARIS, L. Groundsel. 



An annual, about a foot high, with divided leaves and incon- 

 spicuous heads of flowers, somewhat resembling a thistle. In 

 waste places at Columbia Falls and Big Timber. From Europe. 



111. *SILENE NOCTIFLORA, L. Catchfly. 



An introduced annual noted in fields and waste places about 

 Bozeman. An herb one or two feet high, with sticky hairs, op- 

 posite leaves and white flowers. Unlikely to become troublesome 

 in this state. 



