Caulophyllum thalictroides

Blue Cohosh fruit

Blue Cohosh fruit

Blue cohosh, a species of Caulophyllum (family Berberidaceae), also called squaw root or papoose root, is a flowering plant in the Berberidaceae (barberry) family. It is a medium-tall perennial with blue berry-like fruits and bluish-green foliage.

Spreading and bushy when mature, blue cohosh is a large, many-stemmed perennial, 1-3 ft. tall. Thrice-compound leaves with lobed leaflets are purplish in spring. Inconspicuous, purplish-brown to yellow-green flowers in a loosely branched cluster. Clusters of flowers are followed by conspicuous, bright-blue berries.

The six stamens and central pistil of this early spring flower mature at different times, assuring cross-pollination. The petals bear fleshy nectar glands that are visited by early solitary bees. The ovary is eventually ruptured by the developing seeds within it; the seeds are thus exposed, an unusual condition among flowering plants. The seeds have reportedly been used as a coffee substitute, but may also be toxic. The foliage resembles meadow rues (Thalictrum), hence the species name.

Blue Cohosh flowers, early fruits.

Blue Cohosh flowers, early fruits.

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  1. First Flower: Date the first flowers are fully open. When open, you will see the stamens among the unfolded petals.
  2. Full Flower: Date when half or more of the flowers are completely open
  3. First Ripe Fruit: Date when you notice the first fruits becoming fully ripe or seeds dropping naturally from the plant. Ripening is indicated by the berries turning red, yellow, orange, or maroon.
  4. Full Fruiting: Date when half or more of the fruits are completely ripe or seeds are dropping naturally from the plant.
  5. All Leaves Withered: Date when most or all of the leaves that developed this season, have lost green color or are dried and dead.


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