Blue Cohosh

Blue Cohosh

Caulophyllum thalictroides

   
Family

Berberidaceae (Barberry)

Nativity

Native

Status

 

Flowering

April to May

Habitat

Moist. Woods.

Flower Color

Yellowish green

Height

1 to 3


Identification

This is a 1 to 3 tall, erect, perennial forb that rises on multiple stems from a rhizome.

The stems are erect, hairless, and unbranched. They bear just 2 leaves, the first just above the middle, the second just below the inflorescence.

The first leaf is compound, triternate, and stalkless. It divides at the base into 3 long stalks. Each stalk is again divided into 3 shorter stalks. At the end of each of these shorter stalks are 3 leaflets. The overall appearance is of 3 biternate leaves. The 27 leaflets are broad, inversely egg-shaped, 2 to 3 long, and ¾ to 4 wide. They are usually 2- to 5-lobed near the tip, but they may be unlobed. When young they are covered with a whitish, waxy coating. The margins are untoothed. The upper and lower surfaces are hairless. The second leaf is similar to the first but smaller.

The inflorescence is a small, branched cluster of 5 to 70 flowers at the end of the stem.

The flowers are to ½ wide. There are 3 or 4 sepal-like bracts that drop early. There are 6 petal-like, yellowish green, widely spreading sepals. The 6 petals are reduced to gland-like nectaries, are opposite the sepals, and are much shorter than the sepals. In the center of the flower are 6 stamens with yellow anthers surrounding a green ovary.

The fruits never develop. Two large growing seeds rupture the ovary. The seeds are borne naked in pairs on short stems at the end of the elongated pedicel above the leaves. The seeds are have a dark blue, fleshy seed coat. The seed coat is covered with a whitish, waxy coating, making the seed appear light blue.


Similar
Species

May-apple (Podophyllum peltatum) leaves are not compound. The flower droops from the axil of two leaves. The fruit is a yellow berry.

Twinleaf (Jeffersonia diphylla) leaves are divided into 2 kidney-shaped segments. The flowers are borne on a leafless flower stalk. The fruit is brownish and capsule-like.


Range

Throughout

 
Sightings

Carley State Park

Kilen Woods State Park

Murphy-Hanrehan Park Reserve

Comments

 


Images Click on an image for a larger view.
  Blue Cohosh   Blue Cohosh   Blue Cohosh   Blue Cohosh
               
   

Synonyms

 

   

Common
Names

Blue Cohosh

Papooseroot

Papoose-root

Squawroot

Squaw-root

               

 

About Us | Privacy Policy | Contact Us | ©2009 MinnesotaSeasons.com