Stems usually yellow, rarely reddish purple, medium. Inflo­rescences: bracts elliptic to ovate, membranous, margins entire, apex acute. Pedicels absent. Flowers 5-merous, 3–4.2 mm, fleshy; papillae absent; calyx golden yellow, cam­pan­ulate, ± equaling corolla tube length, divided 1/3–1/2 its length, cellular-reticulate, shiny, lobes broadly triangular to obovate, each with a distal fleshy appendage, bases overlapping, margins entire, apex acute to acuminate; corolla white, drying creamy yellow, campanulate, globose or urceolate in fruit, 2.5–4 mm, not saccate, tube 1.5–2 mm, lobes spreading, ovate-orbiculate, shorter than to equaling corolla tube length, margins entire, apex obtuse, straight; infra­staminal scales oblong to ovate, 1.4–1.8 mm, shorter than to equaling corolla tube length, bridged at 0.3–0.5 mm, base truncate to rounded, fimbriate in distal 1/2, fimbriae 0.1–0.2 mm; stamens exserted, shorter than corolla lobes; filaments 0.3–0.6 mm; anthers 0.3–0.6 × 0.3–0.4 mm; styles slightly subulate; style plus stigmas 0.8–1.6 mm, equaling or longer than ovary; stigmas cylindric to terete, 0.4–0.7 mm, shorter than to as long as styles. Capsules depressed-globose, 1.5–2.3 × 1.6–2 mm, not thickened or raised around interstylar aperture, translucent, capped by withered corolla. Seeds 3 or 4, angled, ovoid to broadly ellipsoid, 0.8–1.1 × 0.6–0.7 mm, hilum region terminal. 2n = 14, 28.

Flowering May–Sep. Hosts: primarily Medicago sativa and Trifolium, sometimes other herbs; 200–2500 m; introduced; B.C.; Calif., Colo., Idaho, Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., Utah, Wash., Wyo.; Europe; w Asia; n Africa.

Cuscuta approximata is distinguished from C. epithymum by glomerules usually with more numerous flowers, calyx golden yellow, reticulate, and shiny, and calyx lobes each with a distal fleshy appendage.