Heliotropium curassavicum
Heliotropium curassavicum, commonly called salt heliotrope, is a species of flowering plant in the family Heliotropiaceae. It is native to the Americas and has been introduced elsewhere.
Description
Heliotropium curassavicum is a perennial herb which can take the form of a prostrate creeper along the ground to a somewhat erect shrub approaching in height. The stem and foliage are fleshy, with the leaves thick and oval or spade-shaped.The plentiful inflorescences are curled, coiling double rows of small bell-shaped flowers. Each flower is white with five rounded lobes and a purple or yellow throat. The fruit is a smooth nutlet.
Taxonomy
There are five currently recognized varieties. These are:- H. curassavicum var. argentinum - Native to the tropics of South America, including Argentina, Brazil, Paraguay, and Uruguay.
- H. curassavicum var. curassavicum - Globally widespread, native from the eastern U.S. to Argentina, and naturalized on seashores elsewhere. It has the smallest flowers, being only 2.5–3.5 mm wide
- H. curassavicum var. fruticulosum - Endemic to the San Juan and Mendoza provinces of Argentina.
- H. curassavicum var. obovatum - Widespread in western North America and Chihuahua, Mexico. Its flowers are 5–10 mm wide, with yellow or slightly purple-tinged throats.
- H. curassavicum var. oculatum - Native from southwestern Utah to Baja California. Its flowers are 3–5 mm wide with purple throats.
Distribution and habitat
The species is native to much of the Americas, from Canada to Argentina, including the West Indies and Hawaii. It can be found as an introduced species in Africa, Eurasia, and Australia.It thrives in salty soils, such as beach sand, alkali flats, and salt marshes. It is often found in disturbed coastal sites.