Echinacea serotina, the narrow-leaved purple coneflower or blacksamson echinacea, is a species of flowering plant in the family Asteraceae. It is native to the states of Arkansas and Louisiana in the United States.Nuttall, Thomas 1818. Genera of North American Plants 2: 178 as Rudbeckia purpurea var. serotina Nutt. The species is sometimes listed as being found only in Louisiana, but the type collection was made in Arkansas, part of Louisiana at the time.Tropicos, Rudbeckia purpurea var. serotina Nutt
Echinacea serotina is very similar to E. purpurea but with stiffer, bristly hairs on the foliage.Bailey, Liberty Hyde 1914. Standard Cyclopedia of Horticulture 2: 1088. as Echinacea purpurea var. serotina (Nutt.) L.H. Bailey
References