Caulophyllum giganteum
Caulophyllum
early blue cohosh, giant blue cohosh, northern blue cohosh
blue cohosh, caulophylle, cohosh
nodose, producing 2 leaves per year.
present.
2-7 dm.
1st leaf (2-)3-ternate; 2d leaf (1-)2-ternate;
leaflets 5-10 × 3-8 cm.
blade broadly obovate in overall outline;
rachis pulvinate;
leaflet blades broadly obovate, entire or lobed, margins not toothed;
venation pinnate to palmate.
with 4-18 flowers.
terminal, compound cymes.
bracteoles 2-4 mm;
sepals purple, red, brown, yellow, 6-9 × 1-4 mm, laterally revolute;
petals 2-3 mm;
stamen filaments 1.5-2.5 mm;
pistil 3-5 mm;
style 1-2 mm.
3-merous, 6-20 mm;
bracteoles caducous, 3-4, sepaloid;
sepals 6, yellow, purple, red, brown, or green, petaloid;
petals 6, fan-shaped, bearing nectar;
stamens 6;
anthers dehiscing by 2 apically hinged flaps;
pollen exine reticulate;
ovary bladderlike;
placentation appearing basal;
styles eccentric.
not developed, ovary wall soon rupturing.
2, elevated on elongating stalk, naked at maturity;
seed coat blue, fleshy, glaucous;
aril absent.
= 8.
= 16.
Caulophyllum giganteum
Caulophyllum
Caulophyllum giganteum has a relatively northern distribution, and it flowers precociously; C. thalictroides has a broader distribution, extending farther south, flowers and fruits later, and is less precocious. Caulophyllum giganteum is treated as part of C. thalictroides by most authors.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species 3 (2 in the flora).
Caulophyllum species are understory herbs of mesophytic forests, alluvial flats, rich mesic slopes, and limestone slopes. The seeds of Caulophyllum are buoyant and showy and may be dispersed by water as well as other means; seed germination is hypogeal, the cotyledons remaining underground. Caulophyllum is occasionally cultivated in woodland gardens.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Pistil 3–5 mm; style 1–2 mm; stamen filaments 1.5–2.5 mm; sepals 6–9 mm; inflorescences with 4–18 flowers; 1st leaf (2–)3-ternate; leaflets 5–10 cm. | C. giganteum |
1. Pistil 1–3 mm; style 0.25–1 mm; stamen filaments 0.5–1.5 mm; sepals 3–6 mm; inflorescences with 5– 70 flowers; 1st leaf 3(–4)-ternate; leaflets 3–8 cm. | C. thalictroides |
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