THE MONTANA EXPERIMENT STATION. 



38. CNICUS ERIOCEPHALUS, Gray. Mountain Thistle. 



A tall unbranchcd thistle with a mass of heads aggregated at 

 L^MMjM0$m-i. j ,,, the top of a thick, hollow, leafy, 



stalk, frequent in mountain 

 meadows and pastures above 

 5,000 feet altitude. Rarely so- 

 abundant as to be trouble- 

 some. 



39. CNICUS LANCEOLATUS, 



Willd. Scotch Bull Thistle. 



The second outlawed weed 

 of the state. A European 

 biennial sparsely introduced 

 along the railroads of the 

 state, but nowhere observed 

 to be troublesome except in 

 the Flathead valley about 

 Demersville. It is easily des- 

 Fig. 7. b. Cnicus arvensis, Hoffm. Leaf troyed by digging up the 



and head about natural size; . " , r ,, , , , 



plants before they bloom and 



should not be allowed to secure a foothold. The plant is very 



similar to our native thistle described below, but has much less 



of the cottom r tomentum on the under side of the leaves and the 



leaves and heads are exceedingly prickly with long yellow spines. 



[Fig. 8.] 



40. CNICUS UNDULATUS, Gray. Field Thistle. 



The common thistle of the plains and valleys throughout the 

 state and troublesome in many places, particularly in fallow land, 

 old fields, pastures and meadows, replacing C. eriocephalus below 

 5,000 feet; biennial, or sometimes apparently perennial with 

 deeply penetrating roots. A tall, branched thistle with scat- 

 tered heads and leaves covered with a dense cotton v tomentum. 



