Apocynum cannabinum

Apocynum cannabinum (commonly known as Indian hemp) is a species of plant.  It is also known as Dogbane, Amy Root, Hemp Dogbane, Rheumatism Root, and Wild Cotton.  It is native to all of North America.  It blooms from June to August.  This species is found in moist lowlands, near stream edges, and near pond edges.  It likes to grow in sandy or gravelly soil.  Its height is 1–4 feet.

Other websites

Apocynum cannabinum at USDA PLANT Database
Apocynum cannabinum at Kansas Wildflowers and Grasses 
Apocynum cannabinum at Evergreen Native Plant Database

Category:Apocynaceae