Ammophila breviligulata

American beachgrass
American beachgrass in November; note the characteristic seed heads rising above the leaf spikes. Kohler-Andrae State Park on Lake Michigan.
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
(unranked):	Commelinids
Order:	Poales
Family:	Poaceae
Genus:	Ammophila
Species:	A. breviligulata
Binomial name
Ammophila breviligulata Fern.

Ammophila breviligulata (American beachgrass or American marram grass) is a species of grass that is native to eastern North America, where it grows on sand dunes along the Atlantic Ocean and Great Lakes coasts. Beachgrass thrives under conditions of shifting sand, sand burial, and high winds; it is a dune-building grass that builds the first line of sand dunes along the coast. Beachgrass is less vigorous in stabilized sand, and is only infrequently found further inland than the coastal foredunes. A. breviligulata was introduced to the Pacific coast of North America in the 1930s. It is proving to be invasive, and is increasingly important to coastal ecology and development in Oregon, Washington, and British Columbia.

The leaves of A. breviligulata have deeply furrowed upper surfaces and smooth undersides, and grow 2 to 3 feet (0.6 to 0.9 m) tall. The plant's inflorescence is a spike-like panicle that can reach 10 inches (25 cm) long; the seed head appears in late July or August. The species name breviligulata derives from the Latin brevis ("short") and ligula ("tongue"), which refers to a feature of grass leaves called the ligule.

Ammophila breviligulata is quite similar in appearance and ecology to a second species of beachgrass, Ammophila arenaria (European beachgrass). As Nick Page has summarized, "Ammophila breviligulata is distinguished from A. arenaria by smaller ligules (1-3 mm versus 10-30 mm long in A. arenaria), wider and less inrolled leaves, longer flower spike (25-35 cm versus 15-25 cm long in A. arenaria), and scaly rather than puberulent leaf veins on the upper leaf surface."

Both species of beachgrass are noted for their association with stable sand dunes, and observations in regions where they were introduced to coasts indicate that they actually build the first line of dunes on coasts (the foredunes). The plants spread rapidly (6 to 10 feet (1.8 to 3.0 m) annually) through the sand by subsurface runners (rhizomes), and can produce up to 100 stems per clump annually. They can tolerate burial in as much as 3 feet (1 meter) of sand; sand burial stimulates the rhizomes to grow vertically, and is actually essential to plant vigor. The beachgrass species are also very good examples of xerophytes, being able to thrive on arid to semi-arid beach dunes. The plant has several mechanisms for adapting to heat stress or wind. The long narrow leaves can roll or fold, and the rough upper leaf surface, which contains the gas exchange openings (stomata), can orient itself away from wind.

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Wikipedia