Cuscuta runyonii
Bull. Torrey Bot. Club 69: 541, fig. 1. 1942.
Stems yellow-orange, slender to medium. Inflorescences loose, umbelliform or corymbiform; bracts at base of clusters 1, at base of pedicels 0 or 1, ovate to lanceolate, membranous, margins entire, apex acute. Pedicels 0.8–4(–5) mm, sometimes papillate. Flowers 5-merous, 2.5–3.5(–4) mm, membranous, papillate on perianth, ovary, and capsule; calyx reddish brown, cupulate, shorter than or equaling corolla tube length, divided 1/2–2/3 its length, ± reticulate, shiny, lobes triangular, bases not overlapping, margins entire, midvein sometimes ± carinate, base of calyx corresponding to each lobe with reflexed spurlike projection 0.1–0.6 mm, apex obtuse to subacute; corolla white, drying reddish brown, 2.2–3.5 mm, tube campanulate-globose, 1.1–1.8 mm, saccate between lines of stamen attachments, lobes reflexed, triangular-ovate to lanceolate, equaling corolla tube length, margins entire, apex acute to acuminate, inflexed; infrastaminal scales obovate to spatulate, 1.1–2 mm, equaling corolla tube length, bridged at 0.2–0.4 mm, rounded, uniformly densely fimbriate, fimbriae 0.3–0.7 mm; stamens exserted, shorter than corolla lobes; filaments 0.4–0.6 mm; anthers 0.4–0.6 × 0.4–0.5 mm; styles filiform, 0.9–1.8 mm, equaling or longer than ovary. Capsules depressed-globose, 1.6–3 × 2–3.4 mm, not thickened or raised around relatively large interstylar aperture, not translucent, 1/2+ enveloped by withered corolla, indehiscent. Seeds 4, angled, ovoid to broadly ellipsoid, 0.9–1.4 × 0.8–1.1 mm, hilum region subterminal.
Phenology: Flowering Mar–Dec.
Habitat: Hosts: Dalea, Dyschoriste, Erigeron, Gutierrezia, Hymenoxys, Justicia, Linum, Melampodium, Nama, Oenothera, Spermolepis, Tetraneuris, Thamnosma, Thelesperma, Tiquilia.
Elevation: 0–200 m.
Discussion
Cuscuta runyonii is closely allied with C. glabrior (M. Costea et al. 2015); it differs in having a spurlike appendage at the base of each calyx lobe.
Selected References
None.