24. Cuscuta howelliana P. Rubtzov, Leafl. W. Bot. 10: 335. 1966.
[E W]
Boggs Lake dodder
Stems yellow to orange, slender. Inflorescences dense, glomerulate, 3–30-flowered, flowers sessile or subsessile, embedded in inflorescence of host; bracts at base of clusters 1, at base of pedicels and/or flowers 0 or 1, lanceolate, membranous, margins entire, apex acute. Pedicels 0–0.6 mm. Flowers 4(or 5)-merous, 3–4 mm, membranous, calyx and corolla papillate; calyx straw yellow, campanulate, equaling or longer than corolla tube length, divided 1/2–2/3 its length, finely reticulate, shiny, lobes triangular-ovate, bases not overlapping, margins entire, midvein not carinate, apex acuminate to long-attenuate, recurved; corolla drying white or creamy white to brownish, 2.8–3.5 mm, tube cylindric-campanulate to urceolate, 1.5–2 mm, not saccate, lobes suberect to spreading, triangular-ovate, equaling corolla tube length, margins entire, apex acute to long-attenuate, recurved; infrastaminal scales oblong-ovate, 1–1.3 mm, 1/2–2/3 corolla tube length, bridged at 0.2–0.3 mm, rounded, uniformly densely fimbriate, fimbriae 0.1–0.3 mm; stamens included, shorter than corolla lobes; filaments 0.1–0.3 mm; anthers 0.4–0.5 × 0.3–0.4 mm; styles filiform, 0.4–1.1 mm, 1/4 to ± equaling ovary. Capsules globose to depressed-globose, 1.2–1.5 × 0.8–1.2 mm, not thickened or raised around relatively small interstylar aperture, not translucent, completely enclosed or capped by withered corolla, indehiscent. Seeds 1–4, obcompressed to slightly angled, subglobose to broadly ellipsoid, 0.9–1.2 × 0.8–1.1 mm, hilum region subterminal.
Flowering Aug–Sep. Hosts: Diplacus, Downingia, Epilobium, Eryngium, Navarretia, Polygonum; vernal pools; 30–1000 m; Calif.
Inflorescences of Cuscuta howelliana develop inside inflorescences of Epilobium densiflorum, Eryngium, and Navarretia; the flowers apparently synchronize their anthesis with that of the host’s flowers and achieve both protection from the host and access to the pollinators of the host. When it parasitizes Diplacus and Downingia, the parasite flowers but does not produce seeds.
