Distichlis is a genus of grasses in the family Poaceae, order Poales, distributed primarily across the Americas with one species native to Australia. The genus comprises roughly ten species of low-growing, perennial grasses that spread by rhizomes or stolons, forming dense mats or turf in saline and alkaline habitats such as salt marshes, tidal flats, and alkaline meadows.
All members of the genus are dioecious — male and female flowers are borne on separate plants — a relatively uncommon trait among grasses. The leaves are characteristically distichous, meaning they are arranged in two opposite ranks along the stem, a feature reflected in the genus name itself. Leaf blades are typically stiff and narrow.
The most widespread species is Distichlis spicata (saltgrass), which ranges from Newfoundland and the Northwest Territories of Canada south through Central America to Uruguay, including the Bahamas, Greater Antilles, and the Galápagos Islands. It is one of the dominant grasses of North American salt marshes and saline inland flats. Distichlis distichophylla is the sole Australian member of the genus. Andean species such as Distichlis humilis occur at high elevations in Peru, Bolivia, Chile, and Argentina.
Etymology
The genus name Distichlis derives from the Greek distichos, meaning "two-ranked" or "in two rows," referring to the conspicuously distichous (two-ranked) leaf arrangement characteristic of all species in the genus.
Distribution
Distichlis is distributed across the Americas from Canada (Newfoundland, Northwest Territories) south to Uruguay, encompassing the Bahamas, Greater Antilles, and the Galápagos Islands, with additional species in Argentina, Chile, Bolivia, Peru, Mexico, and California. One species, Distichlis distichophylla, is native to Australia.
Ecology
Species of Distichlis are characteristically halophytic (salt-tolerant), colonizing salt marshes, coastal tidal flats, saline meadows, and alkaline inland basins. They spread clonally via rhizomes or stolons and often form extensive monospecific stands. Distichlis spicata is a dominant component of North American salt-marsh plant communities.
Cultural Uses
Distichlis palmeri, known as Nipa or Palmer's saltgrass, has historical significance as a grain crop among indigenous communities of the Sonoran Desert region; its seeds were harvested as a food source. Distichlis spicata has been investigated as a salt-tolerant turfgrass and forage grass for saline soils where conventional crops cannot grow.
