310 CONVOLVULUS FAMILY. 



5. E VOLVULUS. (From Latin for unroll ; that is, it does not twine.) 

 Low and diminutive small-flowered plants. Flowers summer. 2 



E. argenteus, Pursh. Tufted from a woody base, 5'-7' high, silky- 

 woolly all over ; broadly lanceolate leaves crowded, usually nearly sessile, 

 as are the flowers in their axils; corolla purple, ' broad. Plains, 

 Dak., S. 



E. serlceus, Swartz. Damp ground Fla., W.; slender-stemmed, silky 

 with fine appressed hairs, except the upper face of the scattered lance- 

 linear leaves ; corolla white or bluish, not % f broad. 



6. CUSCUTA, DODDER. (Old name, of uncertain derivation.) 

 Plants resemble threads of yarn, yellowish or reddish, spreading over 

 herbs and low bushes, coiling around their branches, to which they 

 adhere, robbing them of their juices. Flowers small, mostly white, 

 clustered. 



* Stigmas slender; pod opening by a transverse division all round near 

 the base, leaving the partition behind. Natives of Eu. ; flowers early 

 summer. 



C. Epilinum, Weihe. FLAX DODDER. Growing on flax, which it 

 injures ; occasionally found in our flax fields ; flowers globular, in scat- 

 tered heads ; corolla 5-parted. 



* * Stigmas capitate ; pods bursting irregularly if at all ; wild species of 

 the country, mostly in rich or low ground ; flowers summer and 

 autumn. (1) 



-i- Sepals united; ovary and pod depressed- globose. 



w. Flowers sessile in compact mostly continuous clusters ; corolla with a 

 short and wide tube, remaining at the base of the ripe pod; styles usually 

 shorter than the ovary. 



C. arv^nsis, Beyr. On low herbs, in fields and barrens from N. Y., S. 

 and W.; flowers earliest (June, July) and smallest; tube of corolla 

 shorter than its 5 lanceolate, pointed, spreading lobes, much longer than 

 the stamens. 



C. chlorocarpa, Engelm. On low herbs, in wet soil, from Del., W. 

 and S. W.; orange-colored ; open bell-shaped corolla with lobes about the 

 length of the mostly 4 acute lobes and the stamens ; pod large, depressed, 

 greenish-yellow. 



++ -w- Flowers panicled or in compound cymes, the withered corolla re- 

 maining on the top of the pod ; styles mostly longer than the ovary. 



C. tenuif!6ra, Engelm. On shrubs and tall herbs, Pa., W. and S., in 



swamps ; pale ; tube of the corolla twice the length of its ovate, acute, 

 spreading lobes, and of the ovate blunt calyx lobes. 



H- *- Sepals united; ovary and pod pointed. 



C. infl^xa, Engelm. On shrubs and tall herbs in prairies and barrens, 

 N. Eng., W. and S.; corolla fleshy, mostly 4-cleft, its tube no longer than 

 the ovate, acutish, crenulate, erect or inflexed lobes of the corolla and 

 the acute, keeled calyx lobes. 



C. decdra, Engelm. Wet prairies 111., S. W. ; with larger flowers, the 

 corolla broadly bell-shaped, its 5 lobes lance-ovate, acute, and inflexed. 



C. Gron6vii, Willd. The commonest E. and W.; on coarse herbs and 

 low shrubs in wet places ; bell-shaped corolla with tube usually longer 

 than its 5 (rarely 4) ovate blunt spreading lobes ; its internal scales large 

 and copiously fringed. 



