Glabrous perennial with scattered stems from stout creeping roots, somewhat fleshy, prostrate or decumbent, 2-5 dm; lvs linear or linear- oblanceolate, 1-4 cm נ2-5 mm; spikes seldom over 5 cm, the terminal ones usually paired on a peduncle, the lateral usually solitary and sessile or nearly so; cor 2-3.5 mm wide, white with a yellow eye; mature cal spreading; fr depressed-ovoid, 1.5-2.5 mm, soon splitting into 4 nutlets; 2n=26, 28. Native of tropical Amer., established as a weed, especially in saline soil, in s. U.S. n. to Del. and occasionally as a weed farther n. May-Sept. Ours are var. curassavicum. The well marked var. obovatum A. DC. (H. spathulatum) of interior w. U.S., with broader, more oblanceolate or even oblate lvs 6-18 mm wide and with the cor 5-9 mm wide, often with a purple eye, may possibly extend to w. Minn.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Wiggins 1964, Felger 2000, Kearney and Peebles 1969, McDougall 1973
Duration: Annual Nativity: Native Lifeform: Subshrub General: Perennial herbs or rarely annuals, 10-50 cm tall, from rhizomes that send up scattered shoots; stems diffusely branched, semisucculent, bluish-glaucous, and entirely hairless. Leaves: Nearly sessile, alternate; blades mostly 2-6 cm long, 3-10 mm wide, lanceolate to oblanceolate or obovate with acute to rounded tips, fleshy, the surfaces glabrous and glaucous, often purplish in age. Flowers: White, in helicoid spikes, these sometimes in clusters of 3 or 4 at branch tips, tightly scorpoid at the tip in youth; corollas funnel-shaped, 3-6 mm wide, white with yellow center and fading purplish. Fruits: Depressed-globose, about 2 mm diameter, separating in to 4 ovoid nutlets, these rounded and smooth or faintly rugulose on the back. Ecology: Found in marshy soil, alkaline or saline soils, often along wetlands and in irrigated areas, below 5,000 ft (1524 m); flowers most of the year. Distribution: Widely distributed in the warmer parts of the Western Hemisphere. Notes: This blue-tinged, smooth-stemmed herb favors moist, saline habitats and is easily noticed by its attractive curling spikes of white small white flowers at the tips of stems. Its congener, Heliotropium convolvulaceum, is also found in the region but the two species look very different. H. convolvulaceum has hairy herbage and much larger flowers which are usually solitary in leaf axils rather than being arranged in helicoid spikes. The genus Heliotropium has at times been placed in 3 different families: Boraginaceae, Hydrophyllaceae, and Heliotropaceae. Ethnobotany: Seeds were made into a mush and eaten; the plants was also used to treat diarrhea, sore throats, venereal disease, and measles; it was used as a diuretic and an emetic, and pulverized roots were applied to sores and wounds. Etymology: Heilotropium is from the Greek helios, "sun," and trope, "turning," thus meaning "sun-turning;" curvassicum refers to Curacao, the island in the Dutch West Indies. Synonyms: None Editor: SBuckley 2010, AHazelton 2015