Caulophyllum thalictroides blue cohosh Berberidaceae CATH; Bx, pb, vc, wv (Yost et al. 1991); R, gb;

Caulophyllum Herbarium, University of Wisconsin-Stevens Point

Caulophyllum thalictroides. Herbarium, University of Wisconsin-Stevens Point (Accessed 12/2014).

Caulophyllum thalictroides is a perennial herb from a large root crown, root system large, perennial, associated with VA mycorrhizas (Brundrett and Kendrick 1988); stems and leaves waxy-pale (glaucous), a summer green herb (Hicks and Chabot 1985), however leaves tend to die off if no fruit is produced. 

Leaves mostly one per stem, twice 3 times compound, leaflets irregularly lobed, 4-5 cm long, about 3 cm wide, veins palmate at base. 

Caulophyllum Wang.4/2016. Torrey field trip

Caulophyllum Wang.4/2016. Torrey field trip

Flowers yellow-green or purplish, 6-parted, sepals about 1 cm long, larger than petals (Yatskievych 2006); blooming April-May. 

Fruit naked seeds blue, developing seeds breaking through ovary wall (Hannan and Prucher 1996). Seeds apparently dispersed by ingestion. Migration to distant or disconnected forest sites has been estimated at a rate of 0.19 m/yr (Matlack 1994). 

Wetland status: UPL. 

Frequency in NYC: Very infrequent. Origin: Native. 

Habitat: An interior herb of moist forests (Matlack 1994), soil pH 4.5-7.0 (USDA 2006). Shade tolerant summer green herb. Leaves live 20 weeks. Requires at least 1.0% sunlight in order to survive (compensation point), but cannot use more than 30% full sunlight (saturation point) (Hicks and Chabot 1985).