32a. Cuscuta obtusiflora Kunth var. glandulosa Engelmann, Trans. Acad. Sci. St. Louis. 1: 492. 1859.
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Cuscuta glandulosa (Engelmann) Small
Stems orange, slender to medium. Inflorescences dense, glomerulate; bracts at base of clusters 1, at base of pedicels and/or flowers 0 or 1, ovate, membranous, margins entire, apex acute to obtuse. Pedicels 0–1 mm. Flowers 5-merous, 1.8–2.5 mm, membranous, not papillate; calyx yellow-brown, shallowly cupulate, equaling corolla tube length, divided 1/2 its length, not reticulate or shiny, lobes ovate, bases barely overlapping, margins entire, midvein not carinate, apex obtuse; corolla creamy white, drying yellow-brown, 1.6–2.5 mm, tube campanulate, 1–1.5 mm, not saccate, lobes spreading, ovate to ovate-oblong, shorter than to equaling corolla tube length, margins entire, apex obtuse to rounded, straight; infrastaminal scales oblong to obovate, 1–1.5 mm, equaling corolla tube length, bridged at 0.2–0.5 mm, rounded, with relatively few basal fimbriae, densely fimbriate in distal 1/2 or uniformly sparsely fimbriate, fimbriae 0.2–0.6 mm; stamens exserted, shorter than corolla lobes; filaments 0.4–0.6 mm; anthers 0.3–0.4 × 0.2–0.4 mm; styles uniformly stout, 0.4–1.1 mm, equaling or shorter than ovary. Capsules depressed-globose, 1.5–3 × 2.5–4 mm, not raised or thickened around relatively large interstylar aperture, not translucent, base enveloped by withered corolla, indehiscent. Seeds (3 or)4, obcompressed, broadly ovoid to broadly ellipsoid, 1.4–1.5 × 1.2–1.3 mm, hilum area subterminal.
Flowering Jun–Sep(–Oct). Hosts: Alternanthera, Dalea, Hygrophila, Justicia, Ludwigia, Lythrum, Persicaria, Xanthium; stream banks, margins of lakes, swamps, flood plains; 20–600 m; Ala., Ark., Calif., Fla., Ga., Ky., La., Miss., N.Y., Okla., Tex.; Mexico; West Indies (Cuba, Puerto Rico).
Variety glandulosa is similar morphologically to Cuscuta polygonorum; it differs in its five-merous flowers, obtuse corolla lobes, and densely fimbriate infrastaminal scales. Both taxa are usually parasitic on Persicaria. Variety glandulosa differs from C. gronovii var. latiflora in its depressed-globose capsules that are not thickened or raised around the relatively large interstylar aperture.