Key to Weeds 



For weeds among the grasses and composites, see the keys on pages 33 and 50 



mple 

 a. Leaves not lobed or i m 



(1) Plants rosette-like, mat like or creeping 



(a) Leaves lar^'-. S 10 cm. or more, rounded; biennials or perennials 

 x. Leaves elliptic to ovate, in a rosette 



Leaves parallel veined 



is netted-veined, very large 

 m. Leaves densely woolly, hairy 

 n. Leaves not woolly 

 y. Leaves round, on creeping stems 



(b) Leaves small, l-.i cm. linear to ovate, annuals 

 \. Leaves and stem thick and fleshy, not milky 

 y. Leaves and stem milky 



Leaves and stems hairy 



(y) Leaves and stems smooth 



in. Seeds faintly transversely ridged and pitted 



n. Seeds strongly transversely ridged, not pitted 



z. Leaves and stems neither fleshy nor milky 

 (x) Leaves narrow, in whorls 



(y) Leaves broader, alternate 

 in. Flowers solitary in the axils 



n. Flowers clustered in the axils 



(2) Plants erect, ascending, decumbent or climbing 



(a) Stems climbing 



x. Fruits triangular, flowers inconspicuous 



y. Fruits rounded, flowers large white 



(b) Stems not twining nor climbing 

 x. Annuals 



(x) Stems and leaves milky 



Stems and leaves not milky 

 m. Plants bushy, tumble weeds 



(m) Leaves obovate or spoon-shaped 



(n) Leaves linear, somewhat fleshy 

 O. Stems with spiny bracts 

 p. Stems not spiny, often red 



n. Plants not bushy, not tumble weeds 

 (m) Flowers and fruits in terminal clusters or racemes 



Plantdgo mdjor: plantain 



Verbdscum thdpsus: mullein 

 Arctium lappa: burdock 

 Mdlva rotundifdlia: mallow, 



cheeses 



Portuldca olerdcea: purslane 



Euphorbia macula/a: 

 spurge 



Euphorbia serpylli/d/ia: 



spurge 

 Euphorbia glyptosperma : 



spurge 



Mollugo verticilldta: carpet 

 ■weed 



Po lygo num av ic uldre: knot- 

 grass 



Amardnthus blitoides: ama- 

 ranth 



Polygonum convolvulus: 



black bindweed 

 Convolvulus st'pium: hedge 



bindweed 



Euphorbia nutans: spurge 



Amardnthus graccizans: 



tumble weed 



Sdlsola kali: Russian thistle 

 Kochia scopdria: summer 

 cypress 



