19. Cuscuta erosa Yuncker, Illinois Biol. Monogr. 6: 116, plate 2, fig. 8, plate 10, fig. 61. 1921.
[W]
Sonoran dodder
Stems white to creamy yellow, medium. Inflorescences loose to moderately dense, paniculiform or corymbiform; bracts at base of clusters 1, at base of pedicels 0 or 1, ovate-triangular to lanceolate, membranous, margins entire or serrulate-denticulate, apex obtuse to acute. Pedicels 1.5–6 mm. Flowers 5-merous, 3.5–4.5 mm, membranous, not papillate; calyx yellow, cupulate, 3/4 to ± equaling corolla tube length, divided 1/2–2/3 its length, finely reticulate, shiny, lobes orbiculate to oblong-obovate, bases overlapping, margins minutely erose or denticulate, membranous, midvein carinate, apex ± truncate, each not exceeded by a hornlike appendage, 0.1–0.2 mm; corolla creamy white, drying creamy white to reddish brown, 3.2–4 mm, tube campanulate, 1.5–2.2 mm, not saccate, sometimes with horizontal ridges between stamen attachments, lobes erect or spreading to reflexed, oblong-obovate to orbiculate, shorter than to equaling corolla tube length, margins minutely erose or denticulate, membranous, midvein unevenly carinate, apex ± truncate, each with a hornlike appendage 0.1–0.2 mm, not exceeding apex, straight; infrastaminal scales oblong to ± truncate, 1.5–2 mm, 3/4 to equaling corolla tube length, bridged at 0.4–0.6 mm, uniformly densely fimbriate, fimbriae 0.2–0.4 mm; stamens exserted, shorter than corolla lobes; filaments 0.4–1 mm; anthers 0.7–1 × 0.4–0.5 mm; styles stout, subulate, 1.8–3.2 mm, longer than ovary. Capsules globose, 2–2.5 × 2.2–2.5 mm, thickened, not raised around inconspicuous interstylar aperture, not translucent, withered corolla near middle or apical, dehiscence circumscissile. Seeds 1–4, angled, subglobose to ovoid, 0.9–1.4 × 0.8–1.3 mm, papillate, hilum region terminal.
Flowering Aug–Oct. Hosts: Abutilon, Amaranthus, Ambrosia, Anisacanthus, Bidens, Carlowrightia, Euphorbia, Gomphrena, Ipomoea, Jatropha, Justicia, Kallstroemia, Merremia, Mimosa, Rhynchosia, Ruellia, Russelia, Sphinctospermum, Talinum, Tephrosia; desert scrub; 400–1300 m; Ariz.; Mexico (Baja California, Sinaloa, Sonora).
