WEEDS OF MONTANA. 45 



71. LACTUCA SCARIOLA, L. Prickly Lettuce; Chinese 



Lettuce. 



A European biennial resembling the preceding species, but 

 the flowers are light yellow and the leaves are prickly-fringed 

 and not lobed, and have a curious habit of twisting to the vertical 

 with a tendency toward a north and south direction, like a "com- 

 pass plant." A most pernicious weed introduced along the rail- 

 roads in nearly every part of the state but most frequent from 

 Missoula west and south and worst about Plains and Hamilton. 

 It should be destnryed in the localities in which it is established 

 and not permitted to spread and increase the number of our 

 already too numerous European pests. [Fig. 12,] 



72. *LAMIUM AMPLEXICAULE, L. Dead Nettle. 



A European annual introduced with garden seed from the east 

 and well established near Ennis. A prostrate or creeping plant 

 resembling the Ground Ivy, having small, rounded, opposite leaves 

 with purple flowers in the axils. Unlikely to become trouble- 

 some except in irrigated gardens. 



73. *LEONURUS CARDIACA, L. Motherwort. 



A European perennial well established in waste places about 

 Missoula, and one or two other points in the state. 



74. LEPACHYS COLUMNARIS, T. & G. Cone-flower. 



A native perennial of the plains region, one or two feet high, 

 with rough divided leaves and long-stalked flowers with a dark 

 columnar disk and drooping yellow rays. Spreading westward 

 and often troblesome in meadows, pastures and waste places, 

 particularly in dry sandy soil. 



75- LEPIDIUH APETALUH. Willd. Bird-seed; Pepper-grass. 



A small acrid-tasting annual a few inches to a foot high, 

 frequent in dooryards, waste places and cultivated ground. 

 Doubtfully native, although well distributed throughout the 

 plains region. Seeds become mucilaginous when wet and thus 

 facilitate their distribution by animals. 



