26 THE MONTANA EXPERIMENT STATION. 



5. AHARANTHUS BLITOIDES, Wats. Pigweed-Pursley. 



A prostrate-growing, reddish annual, closely related to the 

 preceding and much resembling the eastern "purselev" (Portulaca 

 oleracea, L.) Common in waste places and roadsides east of the 

 Divide and not infrequent as a weed in cultivated ground. Forms 

 mats sometimes three feet in diameter; apparently native. 



6. *AMARANTHUS CHLOROSTACHYS, Willd. Pigweed. 



Closely resembling the next in habit and appearance and popu- 

 larly confused with it, but its fruiting spikes are long and slender 

 and it is much more rare in gardens and waste places. At Colum- 

 bia Falls and Troy; here apparently coming in from the West. 



7. AHARANTHUS RETROFLEXUS, L. Pigweed; Careless Weed. 



A fleshy annual common in our gardens and imported from 

 the East in garden seed; shows little tendency to spread to fields 

 except in rich and moist situations. These four species of amar- 

 anth are easily uprooted and should not be allowed to seed in our 

 gardens. They should be piled, dried and burned to prevent the 

 seeds matured from re-seeding the ground from which they have 

 just been removed. 



8. AMBROSIA ARTEMISI^EFOLIA, L. Ragweed; Hogweed. 



An annual weed, one or two feet high, with opposite many- 

 divided leaves and slender, green-flowered terminal spikelets. This 

 is now coming in from the East along the railways. Frequent on 

 the Great Northern from Havre eastward and occasional as far 

 west as Kalispell. Often abundant in waste places, but with little 

 disposition to take to fields and gardens. 



9. AMBROSIA PSYLOSTACHYA, DC. Creeping Ragweed. 



Occurs occasionally in the eastern part of the state, but has 

 not yet been found very troublesome. It is very similar to the one 

 above, but has long perennial roots tocks which make it difficult to 

 eradicate. 



