Silphium integrifolium - (image 1 of 7)
Taxonomy
Family: Asteraceae
Habitat
Prairies, calcareous fens.
Associates
In prairies with Allium cernuum, Andropogon gerardii, Aster ericoides, Baptisia leucantha, Cassia fasciculata, Coreopsis tripteris, Desmodium illinoense, Eryngium yuccifolium, Fragaria virginiana, Helianthus grosseserratus, Helianthus mollis, Monarda fistulosa, Pathenium integrifolium, Ratibida pinnata, Solidago graminifolia nuttallii, Solidago rigida, Spartina pectinata, Thalictrum dasycarpum hypoglaucum. Associate in calcareous fens include Cacalia pantaginea, Oxypolis rigidior, Parnassia glauca, Valeriana ciliata.
Distribution
Southern MI to NE, south to AL, MI, and TX
Morphology
Coarse, stiff, herbaceous perennial, to 5' high. Leaves opposite, scabrous below, sessile, often clasping, entire or slightly toothed, ovate or lance ovate to elliptic. Stems terete or subterete. Heads many flowered; rays yellow, mostly 16-35, 5 cm long; disk mostly 1.5-2.5 cm wide; phyllaries scabrous or pubescent, eglandular. Fruit an dark, smooth achene, resembles a large sunflower seed.
Notes
Flowers mid July to mid August
Wetland indicator: Upland
Exudes a resinous substance when cut.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of
Northeastern United States
and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois.
Michael Hough © 2005 |