Caulophyllum thalictroides, blue cohosh, is a perennial herbaceous woodland plant that blooms in spring and is native to NJ.
Flowers
Caulophyllum thalictroides, blue cohosh, has inconspicuous unusual flowers
The most conspicuous part of the flower are actually the 6 sepals that are green-yellow (green arrow). Inside the circle of sepals are 6 petals that are short, cupped and fleshy (red arrows). They produce nectar. Next are the 6 stamens about the length of the petals. In the center is the pistil. The style of the pistil frequently bends off center.
Leaves
Leaves:
Look-alikes
There is another species of Caulophyllum that looks like Blue cohosh. It is C. giganteum, and appropriately called Giant Blue Cohosh. Here are two main differences besides size.
- C. thalictroides, blue cohosh
- flowers appearing with the leaves
- flowers usually yellow to yellow-green
- C. giganteum, great blue cohosh
- flowers appearing before expansion of the leaves
- flowers usually purple to purple-brown
See GoBotany for more differences. C. giganteumi> is native to neighboring states but not NJ.
The previously posted photo may have been C. giganteum.
Text by Millie Ling and all photos by Hubert & Millie Ling. Photos: Sourland Mt, Whittingham, Muckshaw parks and preserves, NJ
Additional information
Additional information / references:
- GoBotany compares the two species: https://gobotany.nativeplanttrust.org/species/caulophyllum/thalictroides/