These two varieties are not accepted as distinct by all authorities:[citation needed] It grows on shorelines in tropical and subtropical regions of the Americas and west Africa.

It was introduced in Kuwait and Western Australia due to its propensity to thrive in high temperatures and absorbing brackish water.

They are dark green and shiny on top, and paler with fine silky hairs underneath, and have two salt glands at the base of each leaf.

[6] The fruits are button-like (from which the common names derive), 5–8 mm (0.20–0.31 in) diameter, with no petals; they are produced in stalked panicles of 35-56 flowers.

It is also used as firewood, and is reported to be good for smoking meat and fish, as it burns very hot and slowly; it also makes high quality charcoal.