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GNAPHALIUM, L. Cud- weed, 
f* 510. G. polyeephalum, Michx. Common Everlasting. 
Open woods and fields; frequent. August — September. 
511. G. uliginosum, L. Low Cud-weed. 
Low grounds along roadsides; not common. August. (B. P.) 
INULA, L. 
512. I. helenium, L. Elecampane. 
Roadsides and dry banks ; infrequent or rare. August. (B.) 
The root has a camphoraceous taste and odor. Radical leaves a foot 
or more long. Stem often very tall, 4 to 7 feet. 
POLYMNIA, L. 
- 4 . 513. P. canadensis, L. Leaf-cup. 
Shaded ravines north of Evanston; rare, July. Thatcher, east of 
river; rare, Babcock . d? 3 
SILPHIUM, L. 
514. S. laciniatum, L. Rosin-weed. Compass-Plant. Pilot or Polar- 
weed. 
Banks and prairies; common. July — August. 
The gum that exudes from an injury to this species is sometimes 
employed as a substitute for chewing gum. 
-4 
^ 515. s. tenbinthinaceum, L. Prairie Dock. Rosin-plant. 
Prairies; common, especially south. July — October. 
The wings of the achenia are sometimes nearly as broad as in S. 
laciniata. 
516. s. trifoliatum, L. Rosin-weed. 
Near Thornton, Hill, — in Plants of Illinois. (B.) 
517. S. integrifolium, Michx. Rosin-weed. 
Open prairies ; frequent. August.;’ f 
4 518. S, perfoliatum, L. Cup-plant. 
Maywood. On the banks of the Desplaines river, north of River- 
side; not common, Babcock ! 
PARTHENIUM, L. 
•+"519. P. integrifolium, L. Parthenium. 
Dry sandy soil; common in the eastern portion of our district, else- 
where infrequent. June 25th — August. 
AMBROSIA, Tourn. 
520. A. trifida, L. Great Rag- weed. Horse-weed. 
Banks of streams, lakes, swamps, etc. ; common. August. 
Occasionally 14 feet in height. 
A depauperate form occurs with the type, but does not seem to be 
Var. integrifolia, all the leaves being slightly lobed. 
