14 THE MONTANA EXPERIMENT STATION. 



Their seeds usually are spread by the mud of passage or by the 

 wind. The following species may be enumerated as more or less 

 common in these situations: 



Amaranthus albus, L ''Tumble-Weed." 



A. blitoides, Wats " Pigweed-Purseley . 



Ambrosia trifida, L "Horseweed" (Eastern.) 



A. artemisiaefolia, L "Ragweed. ' ' 



Anthemis Cotula, DC "Dogfennel." 



Arctium Lappa, L "Burdock" (true), rare. 



Artemisia biennis, Willd "Wormwood." 



Atriplex patula hastata, Grav 



Arenaria serpyllifolia, L "Sandwort," rare. 



Brassica campestris, L "Kale." "Wild Mustard." 



Brassica nigra, Koch "Black Mustard;" a rare escape. 



Bromus racemosus, L 



B. tectorum, L 



Capsella Bursa-pastoris, Moench "Shepherd's Purse." 



Chenopodium album, L "Pigweed," common. 



C. Botrys, L ' 'Jerusalem Oak, " common where introduced 



C. capitatum, Wats "Red Pigweed," westward. 



C. hybridum, L "Maple-leaved Goosefoot." 



Cleome integrifolia, Torr. & Gray "Indian Pink," frequent in sandy soil. 



Cnicus arvensis, Hoffm "Canada Thistle," rare. 



C. lanceolatus, Willd "Scotch Bull Thistle." 



Echinospermum deflexum Americanum, 



Gray "Beggar Ticks." 



E. Redowskii, Lehm "Tickseed." 



Ellisia Xj-ctelea, L 



Epilobium paniculatum, Nutt "Cotton weed. " 



Erigeron Canadensis, L "Ragweed," rather infrequent. 



Euphorbia marginata, Pursh 



Franseria Hookerania, Nutt 



Helianthus animus, L "Sunflower," common east of the Divide. 



Hordeum jubatum, L "Foxtail Grass," common. 



Iva xanthiifolia, Nutt "Horseweed," common. 



Lactuea Scariola, L "Prickly Lettuce." 



Lepidium apetalum, Willd "Birdseed," common. 



Madia glomerata, Hook "Tarweed." 



Marrubium vulgare, L "Horehound," infrequent. 



Matricaria discoidea, DC "Rayless Dogfennel," frequent. 



Monolepsis chenopodioides, Moq "Poverty Weed," common. 



Panicum capillare, L "Tumble-grass," frequent eastward. 



Plant ago major, L "Plain tain," infrequent. 



Polygonum aviculare, L "Knotgrass," common. 



