KEY TO WEEDS 



o. Fruit a many seeded 4-celled pod Ondgra biennis: evening 



primrose 

 p. Fruit 1-seeded 



(o) Fruit inclosed in greenish, white or pink sepals, 

 nodes enlarged, stipules sheathing 

 r. Plants 1-3 feet, racemes short and thick Polygonum pennsilvdnicum : 



persicaria 

 s. Plants I-IJ/2 feet, racemes narro\v 



(r) Sepals white or pink Polygonum lapathifolium: 



pale persicaria 

 (s) Sepals greenish Polygonum hydropiper: 



smart-weed 

 (p) Fruit inclosed in fleshy-mealy sepals, stems ridged Chenopodium album: goose- 

 foot 

 (q) Fruit inclosed in dry spiny sepals 

 r. Dull green, spikes dense 



s. Deeper green, spikes slender 



(n) Flowers and fruits in the axils of the leaves 

 o. Fruit a blue-black berry 

 p. Fruit dry, not berries 



(o) Stems four-sided, leaves cordate 



(p) Stems round, leaves ovate to lanceolate 



r. Leaves alternate, fruits surrounded with leafy bracts 

 (r) Leaves parallel-veined, petioles sheathing 



(s) Leaves net-veined, petioles not sheathing 



s. Leaves opposite 



(r) Plants smooth, transparent and watery 

 (s) Plants more or less hairy, not transparent 

 t. Plants tall, fruit 1 cm. or more 



u. Plants low, spreading, fruit less than 1 cm. 

 (t) Leaves all sessile and viscid hairy 



(u) Lower leaves petioled, slightly hairy 

 y. Perennials or biennials 



(x) Leaves densely gray-woolly, large and basal 

 (y) Leaves not woolly, mostly on the stem 

 m. Leaves linear 



n. Leaves oblong to ovate or lanceolate 



(m) Leaves alternate with sheathing stipules 

 (n) Leaves opposite without sheathing stipules 

 o. Margin of leaf entire 



(o) Fruit surrounded by large green involucre 

 (p) Fruit surrounded by close-fitting calyx 



p. _Margin of leaf serrate or toothed 



(o) Flowers in spikes or racemes, leaves not strong 

 scented 

 r. Leaves sessile, spikes dense 



Amardnthus retroflexus: pig- 

 weed 



Amaranth us hybridus: green 

 pigweed 



Soldnum nigrum: nightshade 



Ldmium amplexicaule: hen- 

 bit 



Commelina communis : day- 

 flower 



Acalypha virginica: 3-seeded 

 mercury 



Pilea pumila: clearweed 



Silene nocti flora: night- 

 flowering catchfly 



Cerdstium vulgdtum: mouse- 

 ear chickweed 

 Stelldria media: chickweed 



Verbdscum thdpsus: mullein 



Lindria vulgaris: butter 

 and eggs 



Rumex crispus: dock 



Allionia nyctaginea: 

 Saponaria officinalis: soap- 

 wort 



Verbena stricta: hoary ver- 

 vain 



