3l6 FLOWERS OF FIELD, HILL, AND SWAMP 



fringed. Stamens, 6. Fruit, a pod, notched at the top, 2- 

 celled ; I to 3 blossoms on a stem. 



A beautiful early flower, its peculiar shape suggesting an or- 

 chis, large (i inch long), on slender stems, 4 inches high. 



The flowering branches spring from underground stems. These 

 bear later, small, homely flowers close to the ground, which fer- 

 tilize themselves in the bud. 



22 



P. polygama is taller, 6 to 9 inches high, with simple, leafy 

 stems. Deep crimson flowers in a loose terminal raceme, the 

 wings longer than the keel. From the root, as in the fringed 

 polygala, spring short underground runners bearing a few in- 

 conspicuous, self-fertilizing flowers in racemes. Time, July. 



23. Tick-trefoil 



Desmodium nudiflbrum. — Family, Pulse. Color, purple. 

 Leaves, of 3 leaflets, which are ovate to roundish, pale be- 

 neath. Time, June, Jul}^ 



Corolla, papilionaceous. 



The desmodiums, of which there are many species, are distin- 

 guished by their jointed pods, which are straight on the upper 

 margin, scalloped on the lower. They are covered with bristly 

 hooks, by which they are caught in the hair or fleece of animals 

 and widely scattered. One's feminine skirts are often the medium 

 of such dissemination, much to one's annoyance after a walk in 

 the woods in early fall. All these plants have white and purple 

 corollas, generally rough stems, and variable, 3-foliate leaves. 



The D. 7iudifloru)>i bears racemes of pedicel led flowers on gen- 

 erally leafless scapes 2 feet high. The 3-foliate leaves are nu- 

 merous on the end of a sterile stem, attended by bristly stipules. 

 Pod raised on a stalk longer than the flower pedicels. One of 

 the most common species. 



24 



D. acuminatum bears blossoms and leaves on the same stem. 



