Caulophyllum giganteum – Early Blue Cohosh – 1-Gallon

When we started Catskill Native Nursery in 1999 we thought there was but one species of Blue Cohosh throughout North America. We started collecting seeds in the Catskill Mountains, propagating plants and selling them as the species Caulophyllum thalictroides. In 2003 we came across a publication that indicated there was a second species – Early Blue Cohosh, C. giganteum. The two species can be distinguished fairly easily: in Blue Cohosh, the expansion of the flowers occurs simultaneously with the expansion of the leaves; those flowers range in color from green-yellow to green tinted with purple (rarely entirely purple); they are smaller and more numerous. Early Blue Cohosh appears 10-15 days earlier than Blue Cohosh; expansion of its flowers slightly precedes the expansion of the leaves; the flowers are purple, larger and the inflorescence is sparsely flowered. Foliage is a much darker dusky purple color when it emerges.

Early Blue Cohosh appears to be the predominant species in the Catskills. In fact, we now suspect that Blue Cohosh doesn’t occur in the Catskills at all. Let us know if you think you may have Blue Cohosh (C. thalictroides) growing wild on your property. We’d be interested in collecting seeds.