Cuscuta epilinum
Prodr. Fl. Monast. Westphal., 75. 1824.
Stems yellow-orange, slender to medium. Inflorescences: bracts ovate, membranous, margins entire, apex obtuse. Pedicels absent. Flowers 5-merous, 3–4 mm, membranous; papillae absent; calyx creamy yellow, cupulate, equaling or longer than corolla tube, divided 1/2–2/3 its length, not notably reticulate or shiny, lobes broadly ovate, bases overlapping, margins entire, apex acute to acuminate; corolla white, drying creamy yellow, initially globose, later urceolate, 2.8–3.7 mm, tube 2.5–3 mm, not saccate, lobes erect to spreading, ovate-triangular, 1/4–1/3(–1/2) corolla tube length, margins entire, apex subobtuse to acute, straight to incurved; infrastaminal scales spatulate, 0.8–1.5 mm, 1/2–4/5 corolla tube length, bridged at 0.3–0.5 mm, base truncate, entire or 2-fid, short-fimbriate apically, fimbriae 0.03–0.15 mm; stamens included or barely exserted, shorter than corolla lobes; filaments 0.2–0.4 mm; anthers 0.3–0.5 × 0.3–0.4 mm; styles slightly subulate; style plus stigmas 0.5–1.1 mm, shorter than ovary; stigmas cylindric to terete, 0.3–0.6 mm, ± equaling styles. Capsules depressed-globose, ± angular, 2.8–3.5 × 3–4.2 mm, not thickened or raised around interstylar aperture, not translucent, capped by withered corolla. Seeds 4, usually connate in pairs, angled, subglobose or broadly ellipsoid to ovoid, 1.1–1.2 × 0.9–1 mm, hilum region terminal. 2n = 42.
Phenology: Flowering Jun–Jul.
Habitat: Hosts: primarily Linum usitatissimum but once established on flax, it may also attach to secondary hosts such as Camelina sativa and Guizotia abyssinica.
Elevation: 0–200 m.
Distribution
Introduced; Que., Del., Md., Mass., Mich., N.J., N.Y., Ohio, Pa., Vt., Wash., Wyo., Europe, Asia.
Discussion
Cuscuta epilinum is an ephemeral associated exclusively with flax. It apparently coevolved with flax since its domestication in the Nile Valley or the Middle East (M. A. García and M. P. Martín 2007).
Selected References
None.