Stems 0.3–0.6 mm in diameter, yellow to orange.
Inflorescences loose to dense; pedicels 0.5–6 mm.
Flowers 5-parted, 3–4.5(5.3) mm, fleshy; calyces cup-shaped, 50–75% as long as corolla tube, divided 33–50% of their length, creamy yellow to brownish, not reticulate, not shiny, lobes triangular-ovate, overlapping at base, margins entire, tips acute; corollas campanulate to campanulate-cylindric, 2.5–4(5) mm, white, creamy white to brown when dry, tubes 1.7–3 mm, lobes triangular-ovate, 30–100% as long as tube, erect to nearly so, tips acute, inflexed; stamens enclosed to barely exserted, < corolla lobes, filaments 0.3–0.7 mm, anthers 0.3–0.8 mm, infrastaminal scales ? corolla tube in length; styles evenly filiform, stigmas capitate, globose.
Fruits 2–3.5 × 1.9–4(5) mm, surrounded or capped by withered corollas.
Seeds 2–4.
2n=30.
Parasitic on a wide variety of hosts. Flowering Jul–Dec. 0–900 m. Col, ECas, Owy, Sisk, WV. CA, ID, NV, WA; widespread in North America; South America. Native.
The common name, collared dodder, describes the thickened, elevated ring at the tip of the capsule surrounding the base of the styles, a feature unique to this species among Oregon Cuscuta.