Yellow and Orange ' 



Yellow or Hop Clover 



{Trifolium agrarium) Pea family 



Flcwers — Yellow, scale-like, overlapping in a densely many-flow- 

 ered oblong head about ji in. long, becoming brown with 

 age. Stem: Ascending, branched, o to i8 in. high. Leaves: 

 3-foliate, very finely toothed. 



Preferred Habitat— ^zsXq places, fields, roadsides. 



Flowering Season — May — September. 



Distribution — Virginia to Iowa, and far northward. 



What did the sulphur butterflies provide as food for their 

 caterpillar babies before the commonest clovers came over from the 

 Old World to possess the soil ? Wherever a trifolium grows, there 

 one is sure to see 



" Sallow-^ellow butterflies, 

 Like blooms of lom pnmroses blowing loose. 

 When autumn winds arise." 



The Blackseed Hop Clover, Black or Hop Medic (Medtcago 

 lupulina), with even smaller, bright yellow oblong heads which 

 turn black when ripe, lies on the ground, its branches spreading 

 where they leave the root. A native of Europe and Asia, it is now 

 distributed as a common weed throughout our area, for there is 

 scarcely a month in the year when it does not bloom and set seed. 

 It is still another of the many plants known as the shamrock. 



Yellow Wood-sorrel ; Lady's Sorrel 



{Oxalis stricta) Wood-sorrel family 



Flowers — Golden, fragrant, in long peduncled, small, terminal 

 groups. Calyx of 5 sepals ; corolla of 5 petals, usually reddish 

 at base ; stamens, 10 ; i pistil with 5 styles ; followed by 

 slender pods. Stem: Pale, erect, 3 to 12 in. high, the sap 

 sour. Leaves: Palmately compound, of 3 heart-shaped, 

 clover-like leaflets on long petioles. 



Preferred Habitat— Q^&a. woodlands, waste or cultivated soil, road- 

 sides. 



Flowering Season — April — October. 



Distribution — Nova Scotia and Dakota westward to the Gulf of 

 Mexico. 



An extremely common little weed, whose peculiarly sensitive 

 leaves children delight to set in motion by rubbing, or to chew for 

 the sour juice. Concerning the night •' sleep " of wood-sorrel 

 leaves and the two kinds of flowers these plants bear, see pages 

 107 to 1 10. 



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