Cuscuta occidentalis

Stems yellowish to orange, medium. Inflorescences dense, glomerulate; bracts at base of clusters 1, at base of pedicels and/or flowers 0 or 1, lanceolate to ovate, membranous, margins entire, apex acute to acuminate. Pedicels 0–0.5(–1.5) mm. Flowers 5-merous, 2.7–3.4 mm, membranous, usually not papil­late; calyx usually yellow, campanulate, somewhat shorter than to equaling corolla tube length, divided 2/5–1/2 its length, not reticulate, shiny, lobes narrowly ovate to lanceolate, bases not overlapping, margins entire, midvein not carinate, apex acuminate; corolla white, drying creamy white or yellow, 2.5–3.2 mm, tube cylindric-campanulate, 1.4–2.1 mm, saccate between lines of stamen attachments, lobes usually spreading, sometimes reflexed, lanceolate, shorter than corolla tube length, margins entire, apex acuminate, straight; infrastaminal scales absent; stamens ± exserted, shorter than corolla lobes; filaments 0.2–0.5 mm; anthers 0.2–0.5 × 0.2–0.4 mm; styles filiform, 0.5–1(–1.5) mm, shorter than ovary. Capsules globose to depressed-globose, 1.8–2.2 × 2–2.6 mm, slightly thickened, not raised, around relatively small interstylar aperture, translucent, surrounded by, not completely enclosed by, withered corolla (top of capsule visible), indehiscent. Seeds 2–4, obcompressed, subglobose to broadly ellip­soid, 0.8–1.3 × 0.8–1.1 mm, hilum region lateral.

Phenology: Flowering Mar–Sep.
Habitat: Hosts: Artemisia, Cistanthe, Corethrogyne, Diplacus, Epilobium, Ericameria, Erio­dictyon, Eriogonum, Hemizonia, Iva, Lotus, Lupinus, Monardella, Oenothera, Polygonum, Salvia, Sisym­brium, Trifolium, and others.
Elevation: 200–2500 m.

Distribution

• Generated Map
• Legacy Map

Calif., Colo., Idaho, Nev., Oreg., Utah, Wash., Wyo.

Discussion

Cuscuta occidentalis has been treated as C. californica var. breviflora, in which T. Beliz (1993) also included C. brachycalyx and C. suksdorfii. Cuscuta occidentalis differs from C. californica by its sessile or subsessile flowers, saccate corolla tube, relatively short anthers, relatively short styles, and translucent capsules that are completely enveloped by withered corollas (M. Costea and S. Stefanović 2009). Both C. californica and C. occidentalis are distinguished from C. suksdorfii by five-merous flowers, acute or acuminate calyx and corolla lobe apices, absence of infrastaminal scales, and capsules enclosed by withered corollas (M. Costea et al. 2006b).

Selected References

None.

Lower Taxa

None.