Species Native to Missouri
Common Name: blue cohosh
Type: Herbaceous perennial
Family: Berberidaceae
Native Range: Eastern and central North America
Zone: 3 to 8
Height: 1.00 to 2.00 feet
Spread: 0.50 to 1.00 feet
Bloom Time: April
Bloom Description: Yellow-green
Sun: Part shade to full shade
Water: Medium
Maintenance: Medium
Flower: Insignificant
Fruit: Showy
Culture
Best grown in shady woodland areas in rich, moist, neutral to slightly acidic soils. Needs consistently moist soils that do not dry out. Plants may be grown from seed, but usually will not flower until the third or fourth year. May be divided, but established plants are generally best left undisturbed. Can spread very slowly by rhizomes over time to form colonies.
Noteworthy Characteristics
Caulophyllum thalictroides, commonly called blue cohosh, is a Missouri native perennial which grows 1-3' tall on strong, upright stems. It is valued not for its flowers but for its lacy, ternately-compound, blue-green foliage and its erect clusters of blue, fruit-like seeds. Foliage is suggestive of meadow rue (Thalictrum), hence the species name. Leaves appear at mid-stem, emerging a smoky blue in spring and turning bluish-green at maturity. Young plants are covered with a whitish, waxy bloom. Inconspicuous, brownish-green to yellowish-green flowers (1/2" diameter), each with 6 pointed sepals, appear in spring. Flowers give way in summer to attractive blue berry-like seeds (outer seed coating turns fleshy and blue as seeds mature) which resemble small grapes and provide good ornamental interest into fall after foliage decline has occurred.
Genus name comes from the Greek words kaulos meaning a stem and phyllon meaning a leaf.
Specific epithet means like the genus Thalictrum.
Problems
No serious insect or disease problems. Slow to establish from seed. Berry-like seeds are poisonous.