WEEDS OF MONTANA. 19 



cleared. The work should not be left till the seeds begin to mature, 

 else it will be necessary to remove the plants pulled to prevent 

 them from re-seeding the ground cleared. This method is slow 

 and expensive, especially here in Montana where labor is such a 

 desideratum, and it can rarely be employed with economy. 



In a few instances hand weeding is practically the only method 

 available. This will apply particularly to weeds affecting lawns 

 and meadows. The broad-leaf plaintain can only be dug up one 

 plant at a time, and this is also true of the dandelion and thistles, 

 but with the last two a chisel-like instrument .("spud") with a four 

 foot handle may be employed to cut them off just below the crown 

 of leaves and is usually found effective. 



There are a few species of weeds which are particularly difficult 

 of extermination on account of the spread of underground stems. 

 A few of our native species exhibit this tendency to a greater or 

 less extent, such as the Poverty Weed (Iva axillaris), the Wild 

 Liquorice (Glycyrrhiza lepidota), the Milk-weed (Lactuca pul- 

 chella), the Wild Asparagus (Lygodesmia juncea), the Iron-weed' 

 (Epilobium angustifolium), and the Lupine (Lupinus sericus), but 

 these usually disappear after a few years cultivation and persist 

 onry in specially favored localities, where thev may be treated like 

 the next. But it is from a few foreign introductions that the chief 

 trouble arises and these should be exterminated before they have* 

 become firmly established. The Canada Thistle is the worst and 

 a law has been enacted to enforce its destruction in the state. It 

 is established in many places along the railroads and is frequently 

 imported with garden seed. It is found only in small patches and 

 appears to show little disposition to spread b} r seed in this state. 

 The most effective method to get rid of it is probably to dig it up, 

 removing every particle of the root-stocks and then await growth 

 to indicate the location of any root remnants in the soil. Its 

 growth can be restricted by keeping it cut down, but this will 

 scarcely exterminate it. It can be smothered out by building 

 ttraw or haystacks over the spots affected, or by covering with 

 manure dumps, and it may often be killed by plentifully sprinkling 

 salt or kerosene over the freshly cut stumps. Sodium arsenite 

 is more effective, but also more expensive. 



The wild Morning-glory (Convolvulus arvensis) and the Sheep- 



