KEY TO WEEDS 



petioled, spikes ilendei 

 (r) Floweri in loogi slender terminal s|>ik< s 



Flowera in nnmeroni axillary tpikei 

 (p) Flowers in axillary clusters, leaves strong scented 

 I'. 1 1 av< a lobed or cut 



(1) Leaves opposite 



(a) Stems climbing, rough, almost prickly 



(b) Sinn- miii climbing, square or saoarisb 

 \. Stems prostrate, bracted, fruit unarmed 



y. Stems erect, not bracted, fruits spiny 



(2) Leaves alternate 



Stems climbing, fruit spiny 

 x. Fruits borne singly, four-seeded 



v. Fruits in clusters, one-seeded 



(b) Stems erect or nearly so, fruit mostly smooth 

 \. Fruit small, flattened, 1-seeded, in clusters 



y. Fruit a several to many seeded pod 

 (x) Pod elongated or narrow 

 m. Tod 6-10 cm. long, flowers cream colored 



n. 1'od 1-2 cm. long, flowers yellow- 

 Cm) Pod sessile 



(n) Pod stalked 



0. 1'od 1 cm, or less, shorter than the spreading pedicels 



p. Pod 1-2 cm., longer than pedicels, appressed or ascend- 

 ing 

 (o) Beak ]/j- l A as long as pod 

 r. Pod 10-15 mm. long 

 s. Pod 2-5 cm. long 



(p) Peak very short, pods appn 



(y) Pod rounded or triangular 

 m. Pod large, spiny 



n. Pod small, flat and smooth 

 (m) Pod rounded, 2-seeded 



(n) Pod triangular, many seeded 



2. Leaves compound 



a. Leaves with 3 leaflets 



(1) Leaf-margin entire 



(a) Plants strong-scented, leaflets not notched at apex 



(b) Plants scentless, leaflets notched at apex 



(2) Leaf margin serrate or toothed 



Verbima urtici/dlia: white 



dcilis: nettle 

 A ,'/>! ta i at Aria: catnip 



Humulus lupulus: hop 



l' trhi ! na brdcteosa: bracted 

 vervain 



Leo mi rus card idea: mother- 

 wort 



Micrdmpelis lobdta: wild cu- 

 cumber 



Sicyos anguldtus: star cu- 

 cumber 



Clnno podium hybridum : 



foot 



Sisymbrium altissimum : 



tumble mustard 



Sisymbrium officinale: hedge 

 mustard 



RSripa paliistris: marsh- 



Brdssica ar-'ensis: charlock 

 Brdssica jiincca: Indian 



mustard 

 Brdssica nigra: black mus- 

 tard 



Datura stramonium: jimson 



Lepidium apctalum: pepper- 



grass 

 Bursa btirsa-pastdris: S 



herd's purse 



Polanisia gra'colens : clam- 

 my ' 

 Oxalis strict a: wood sorrel 



