736 WEED FLORA OF IOWA 



{Atriplex hortense), cock's comb (Bhina/nthus crista^galli major 

 and ndiwr), smartweed (Polygonum persicabia), cypress spurge 

 (Euphorbia cyparissias) , meadow saffron ( Colchicum autumnale), 

 silky bent-grass (Agrostis spicchventi) , wild oats (Avbna patua), 

 tfliess (Bromur segatjntjs), quack grass (Agropyeon rbpens), 

 horse-tail (Equisetum arvense). 



L. Danger in his work on weeds and parasites of Germany, pub- 

 lished in 1887, divides the weeds of Germany into two classes: 



A. Root weeds, B. Seed weeds. 



A. Boot weeds. — Quack grass {Agropyron repens), reed grass 

 (Phragmites conumunis), bindweed (Convolvulus arvensis), deadly 

 nightshade {Atropa ielladowna), goatweed {Aegopodium roda- 

 graria), sheep sorrel {Bumex acetosella), sour dock {B. crispus), 

 meadow saffron Colchicum cmtumnale), marsh marigold (Caltha 

 paiustris), mint {Mentha arvensis), thistle {Cirsium arvense, C. 

 alteraceum, C. accmle, C. heterophylhim, C. pahistre, C. lam- 

 ceolatum), {Cardwus crispus, C. lanceolatus, C. natans), {Onopor- 

 don acanthiwm), sow thistle {Sonchus arvensis, S. pahistre, 8. asper, 

 S. oleraceus), colt's-foot {TussUago farfara, T. hybrida, T. peta- 

 sites), yarrow {Achillea millefolium), {Leontodon autumnalis) 

 dandelion {Taraxacum officinale), plantain {Plantago coron^pus, 

 P. arena/ria, P. major, P. media, P. m^ritima, P. lanceolata) , horse- 

 tails {Equisetum arvense, E. pahistre). 



B. Seed weeds. — Chess {Bromus secalinus), {Alopecurus 

 agrestis), wild oats {Avctud fatua), {Agrostis spicorventi) , darnel 

 {Lolium tem/ulentum), black nightshade {Solanum nigrum), black 

 henbane {Hyoscyamus niger), Jimson weed {Datura stramonium), 

 fool's parsley {Aethusa cynapium), hemlock {Conium maculatum), 

 cowbane {Cicuta virosa), Venus' comb {Scandix pecten-veneris) , 

 buckwheat {Fagopyrum esculentum), smartweed {Polygomim 

 persicaria) , dooryard knotweed {Polygonum aviculare) , com cockle 

 {Agrostemma githago), buttercups {Banunculus septentrionalis, 



B. flammula, B. arvensis), nettle {Lamium), charlock {Baphanus 

 raphcmistrum) , foxglove {Digitalis purpurea), mustard {Brassica 

 arvensis) , mayweed {Anthemis arvensis and A. cotvZa) , groundsel 

 {Senecio vulgaris), horseweed {Erigeron canadensis), field mari- 

 gold {Chrysanthemum segetum), Frenohweed {Galinsoga parvi- 

 flora), spurge {Euphorbia cyparissias), orach {Atriplex hortense), 

 nettles {Vrtica urens, U. dioica). 



