Ammophila is a genus of flowering plants consisting of two or three very similar species of grasses. The common names for these grasses include marram grass, bent grass, and beachgrass. These grasses are found almost exclusively on the first line of coastal sand dunes. Their extensive systems of creeping underground stems or rhizomes allow them to thrive under conditions of shifting sands and high winds, and to help stabilize and prevent coastal erosion. Ammophila species are native to the coasts of the North Atlantic Ocean where they are usually the dominant species on sand dunes. Their native range includes few inland regions, with the Great Lakes of North America being the main exception. The genus name Ammophila originates from the Greek words ἄμμος (ámmos), meaning "sand", and φίλος (philos), meaning "friend".
Ammophila arenaria is a species of flowering plant in the grass family Poaceae. It is known by the common names marram grass and European beachgrass. It is one of two species of the genus Ammophila. It is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is a perennial grass forming stiff, hardy clumps of erect stems up to 1.2 metres (3.9 ft) in height. It grows from a network of thick rhizomes which give it a sturdy anchor in its sand substrate and allow it to spread upward as sand accumulates. These rhizomes can grow laterally by 2 metres in six months. One clump can produce 100 new shoots annually.
Swallenia is a rare genus of plants in the grass family, found only in Death Valley National Park, California.
Agrostis densiflora is a species of grass known by the common name California bent grass. It is endemic to the coast of northern and central California, United States, where it grows in habitat along the immediate coastline, such as dunes and bluffs.
Carex pansa is a species of sedge known by the common name sand dune sedge. It is native to coast of western North America from British Columbia to California, where it grows in dunes and other sandy habitat. This grasslike sedge produces sharply triangular stems up to about 40 centimeters tall from a network of thin, long, coarse rhizomes. The inflorescence is a cluster of several spikes of dark brownish flowers. The plant sometimes produces only male or female flowers in its inflorescences, but not both. This sedge is sometimes used as a grass substitute in local landscaping schemes.
Poa atropurpurea is a rare species of grass known by the common name San Bernardino bluegrass. It is endemic to southern California, where it is known from two regions, the San Bernardino Mountains near Big Bear and the Laguna Mountains of San Diego County.
Poa bolanderi is a species of grass known by the common name Bolander's bluegrass. It is native to western North America from British Columbia to Utah to California, where it is a resident of mountain habitat, particularly pine and fir forests. It is an annual grass growing in clumps up to 60 centimeters tall. The inflorescence occupies the top 10 to 15 centimeters of the stem. It is narrow in flower, with branches appressed, growing parallel to the stem. As the fruit develops the branches spread out, becoming perpendicular to the stem, nodding, or drooping. The branches have few, sparse spikelets.
Poa bulbosa is a species of grass known by the common names bulbous bluegrass or bulbous meadow-grass. It is native to Eurasia and North Africa, but it is present practically worldwide as an introduced species. It is widespread in the United States and southern Canada. It was introduced to the eastern United States around 1906 and the western US in 1915 as a contaminant in shipments of alfalfa seed. It was intentionally planted on both the east and west coasts to control weeds and prevent erosion. Today it is a common grass across the continent and is a noxious weed in some areas. It is a sturdy, hardy, persistent, aggressive grass that easily outcompetes many other plants and becomes the dominant species in disturbed habitat types, such as overgrazed fields.
Poa confinis is a species of grass known by the common names coastline bluegrass and beach bluegrass. It is native to the coastline of western North America from British Columbia to northern California, where it grows on beaches, dunes, and other coastal habitat.
Poa cusickii is a species of grass known by the common name Cusick's bluegrass. It is native to western North America from Yukon to Colorado to eastern California, where it grows in many types of habitat, including high mountain meadows and slopes, sagebrush scrub, and forests.
Poa glauca is a species of grass known by the common names glaucous bluegrass, glaucous meadow-grass and white bluegrass. It has a circumboreal distribution, occurring throughout the northern regions of the Northern Hemisphere. It is also known from Patagonia. It is a common grass, occurring in Arctic and alpine climates and other areas. It can be found throughout the Canadian Arctic Archipelago in many types of habitat, including disturbed and barren areas.
Poa howellii is a species of grass known by the common name Howell's bluegrass.
Poa infirma is a species of grass known by the common names early meadow-grass and weak bluegrass. It was first described from a specimen found in Colombia, but it is actually an introduced species in the Americas and is native to Europe. It grows in many types of habitat, including disturbed areas. It is very similar to Poa annua, which is probably a daughter species, and it is often mistaken for P. annua unless it is closely examined.
Poa kelloggii is a species of grass known by the common name Kellogg's bluegrass. It is endemic to the North and Central Coasts of California, where it grows in coastal forests, including redwood forests. It is a perennial grass producing single stems or loose clumps of several stems up to 85 centimeters tall. The inflorescence is a series of branches along the stem which spread out and then droop as the fruit matures. The flattened spikelets occur at the tips of the thin branches.
Poa leptocoma is a species of grass known by the common names marsh bluegrass and western bog bluegrass.
Poa macrantha is a species of grass known by the common names seashore bluegrass and large-flowered sand dune bluegrass. It is native to the west coast of North America from Alaska to northern California, where it grows in sand dunes and other beach habitat.
Poa napensis is a rare species of grass known by the common name Napa bluegrass. It is endemic to Napa County, California, where it is known from only two occurrences near Calistoga. It grows in moist, mineral-rich soil around hot springs. The rare grass only occurs on private, unprotected land and depends on water from the hot springs; changes to the local water regime or any other aspects of its specific habitat type would affect the plant. This grass was federally listed as an endangered species in 1997, along with another rare local hot spring endemic, the Calistoga popcornflower.
Poa unilateralis is a species of grass known by the common names San Francisco bluegrass, ocean-bluff bluegrass, and sea-bluff bluegrass.
Poa diaboli is a rare species of grass known by the common name Diablo Canyon bluegrass. It is endemic to San Luis Obispo County, California, where it is known from about five occurrences in the San Luis Mountains near the coast. The type specimen was collected in Montaña de Oro State Park and the grass was described as a new species in 2003. The grass occurs on rugged mountaintops and north-facing slopes in thin soils covering shale rock within a few kilometers of the coastline. Its habitat includes chaparral, oak woodland, coastal sage scrub, and Bishop pine forest.
Poa paludigena is a species of grass known by the common names bog bluegrass, marsh bluegrass, slender marsh bluegrass, and Patterson's bluegrass. It is native to the northeastern United States.
