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Helianthus decapetalus

Common Name of Species: Thin Leaved Sunflower 
Family: Asteraceae
 


Entry Author:  C. Friedl, Muhlenberg College
Description: 
Thin-leaved sunflowers can be identified by the way their broad leaves narrow abruptly into long, winged stalks, or petioles.
Leaves: 
Leaves are thin, nearly smooth, green on the underside and sharply toothed.  Upper leaves can sometimes be alternating.  Lower leaves, have ¼ inch stalks that narrow quickly from broad leaf. Lower leaf stalks are also winged.
Flowers: 
Flowers are 2-3 inches wide, and yellow.  Despite the scientific name (Helianthus decapetalus), there are not always exactly ten rays that surround the greenish/yellow disk. 
Stem: 
Stems are generally smooth and straight.  
Branching Pattern:  Leaves are most commonly opposite, but can be alternate towards the top.
Height:  
2-5 feet in height. 
Conditions/Habitat: 
Grow in open woods, dry thickets, and forest margins.
Range: 
Throughout eastern North America.

References:
Niering, W.A., Olmstead, N.C, & Thieret, J.W. (2001). National Audubon Society Field Guide to North American Wildflowers Eastern Region (Revised Edition).  New York: Random House Inc.

Newcomb, Lawrence (1977).  Newcomb’s Wildflower Guide.  New York: Little, Brown.
     

McKenny, M. & Peterson R.T. (1996). Peterson Field Guides: Wildflowers Northeastern/ North-central North America. New York: Houghton Mifflin.

USDA, NRCS (2004). Plants Database, Version 3.05 (http://plants.usda.gov).  National Plant Data Center, Baton Rouge, LA 70874 USA.



     

This page was created by: C. Friedl, Muhlenberg College
Last updated 11/10/05