Blue Cohosh

Caulophyllum thalictroides
A slow spreading, clumping perennial, reaching up to 3 x 2 feet in size, that is native to northeastern North America ( from southeast Manitoba to Thunder Bay, Ontario to Batchewana, Ontario to Tobermory, Ontario to Haliburton, Ontario to southeast Quebec to Kedgewick, New Brunswick to Sydney, Nova Scotia; south to northeast Oklahoma to far northern Georgia to central Virginia ). In the Windsor/Essex County, Ontario region; it was abundant around Point Pelee as well as the Lake Erie islands during the 1800s. It also occurred sporadically at Detroit and the Ohio shore during that time. It is found in rich, mixed or deciduous woodland.
The ternately-compound leaves are made up of lobed leaflets each up to 3 inches long. The foliage is purplish at first, turning to blue-green.
The yellowish-green flowers, up to 0.5 inches wide, are borne in loose clusters during late spring.
They are followed by showy, bright blue berries, up to 0.3 inches wide. The berries are not edible and should not be eaten.
Hardy zones 3 to 7 in partial to full shade on moist, fertile, well drained soil that is mulched heavily with chopped leaf compost. It is not prone to insect pests or disease. Propagation is from seed or careful division while dormant.

* photos taken on July 27 2015 in Bayfield, ON

* photos taken on July 16 2016 in Bayfield, ON

* photos taken on July 9 2022 in Bayfield, ON

* photo taken on July 9 2023 @ Scenic Caves, Collingwood, ON

var giganteum
Also called Caulophyllum giganteum. New foliage is deep purplish-green during spring and the flowers appear slightly earlier. It is otherwise very similar.

Caulophyllum robustum
Very similar to Caulophyllum thalictroides but is native to mountain forests of far eastern Russia, Sakhalin, China, Korea and much of Japan.