Caulophyllum
thalictroides (L.) Michx.
Standardized Common
Name: Blue
Cohosh
Other Common Names: Blueberry Root,
Papoose Root, Squaw Root
Family: Berberidaceae
Taxonomy: According to most
treatments, there is one species of Caulophyllum in North America (C.
thalictroides) and one in Asia. Caulophyllum thalictroides var. giganteum
Farw., a variety of C. thalictroides that has on average larger leaves,
fewer and larger flowers, and putatively a later flowering time, is raised to
the rank of species as C. giganteum (Farw.) Loconte & W. H.
Blackwell in a recent treatment. The two “species” are found together over most
of their range, often in mixed populations, and the evidence for their
separation is minimal.
Description: Rhizomatous perennial
herb. Rhizome crooked, branching, to 15 cm long, with numerous long, slender
roots. Stem erect, 30–70 cm high, bearing (1–)2 leaves and a terminal
inflorescence, rarely branching. First leaf (2–)3–4-ternately compound, the
primary rachises long; leaflets 27 or sometimes more, 3–8(–10) cm long, broadly
obovate, usually 2–3-lobed, deep green, glaucous; leaflet bases rounded to
wedge-shaped, often somewhat oblique; leaflet and lobe apices acute.
Inflorescence cymose, racemiform or paniculiform, usually subtended by a
smaller 2-ternately or ternate-pinnately compound second leaf, with
(5–)12–20(–70) flowers. Flowers yellowish-green or maroon-tinged, 3–7 mm in
diameter, with 6 petaloid sepals, 6 small thickened petals, 6 stamens, 1
carpel. Mature “fruit” consisting of naked seeds with fleshy outer layer,
appearing berrylike, deep blue, globose, 6–8 mm in diameter, ripening on flower
stalk after remains of ovary have fallen away.
Parts
in Commerce:
Rhizome with roots
Identification:
- Rhizome crooked,
knotted, branching, (7–)10–15(–25) cm long
- 0.5–1.5 cm
thick, somewhat flattened
- Surrounded by
dense mat of thin unbranched roots, up to 20 cm long, emerging from most
surfaces of rhizome
- Upper surface of
rhizome bearing several large, shallow cup-shaped stem scars, either
depressed or raised, and often remnants of stem bases
- Outside of
rhizome and roots usually a distinctly yellowish pale brown; though
overall form of rhizome is knotted, portions of surface not covered with
roots often look smooth
- Inside of rhizome
yellowish to pale brown, having a waxy appearance
- In
cross-section, contains thin bark and cortex; xylem in numerous narrow
wedges separated by narrow parenchyma rays; large pith
- Roots in
cross-section have usually 4-rayed xylem
- Fracture tough
- Taste bitter,
acrid
Adulterants: Jeffersonia
diphylla (L.) Pers. is reported in historical literature to be an
adulterant, though it could not easily be mistaken for Caulophyllum, as
its rhizome is significantly smaller. There is at present no reason to exclude
material of C. thalictroides var. giganteum from Blue Cohosh in
commerce, and it would probably be impossible to distinguish between rhizomes
of different varieties.
References:
Hannan GL, Prucher HA. Reproductive biology of Caulophyllum
thalictroides (Berberidaceae), an early flowering perennial of eastern
North America. Amer Midl Nat. 1996;136:267–277.
Loconte H. Caulophyllum. In: Flora of North
America Editorial Committee, eds. Flora of North America, vol. 3. New
York, NY: Oxford University Press; 1997:274–275.
Loconte H, Blackwell WH. A new species of blue
cohosh (Caulophyllum, Berberidaceae) in Eastern North America. Phytologia.
1981;49:483.
Loconte H, Blackwell WH. Intrageneric taxonomy of Caulophyllum
(Berberidaceae). Rhodora. 1985;87:463–469.
Radford AE, Ahles HE, Bell CR. Manual of the
Vascular Flora of the Carolinas. Chapel Hill, NC: University of North
Carolina Press; 1968.
Youngken HW. Text-Book of Pharmacognosy, 5th ed. Philadelphia, PA: The
Blakiston Company; 1943:341.
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