Photographer: Merel R. Black
Silphium integrifolium Michx.
prairie rosinweed, whole-leaf rosinweed
Silphium: old Greek generic name referring to resinous juice
integrifolium: Latin for "entire-leaved"
|Plant: ||erect, perennial, 2'-6' tall forb; stems leafy, cylindrical in X-section|
|Flower: ||head 2"-3" wide with 16-33 (usually 21 or 34) yellow rays 3/4"-1" long; disk usually 1/2"-1" wide; inflorescence of many heads in large, branched clusters; blooms July-Sept.|
|Fruit:||dry seed with no fluffy pappus|
|Leaf:||mostly opposite but not surrounding the stem, lower and upper leaves about the same size|
|Habitat: ||full sun; dry, moderate moisture to wet; prairies, meadows; in sandy, loamy soil|