Sporobolus in the context of Grass family

Sporobolus alterniflorus, or synonymously known as Spartina alterniflora, the smooth cordgrass, saltmarsh cordgrass, or salt-water cordgrass, is a perennial deciduous grass which is found in intertidal wetlands, especially estuarine salt marshes. It has been reclassified as Sporobolus alterniflorus after a taxonomic revision in 2014, but it is still common to see Spartina alterniflora and in 2019 an interdisciplinary team of experts coauthored a report published in the journal Ecology supporting Spartina as a genus. It grows 1–1.5 m (3 ft 3 in – 4 ft 11 in) tall and has smooth, hollow stems that bear leaves up to 20–60 cm (7.9 in – 1 ft 11.6 in) long and 1.5 cm (1⁄2 in) wide at their base, which are sharply tapered and bend down at their tips. Like its relative saltmeadow cordgrass S. patens, it produces flowers and seeds on only one side of the stalk. The flowers are a yellowish-green, turning brown by the winter. It has rhizomes, which, when broken off, can result in vegetative asexual growth. The rhizomes are an important food resource for snow geese. Sporobolus alterniflorus grows in low marsh (frequently inundated by the tide) as well as high marsh (less frequently inundated), but it is usually restricted to low marsh because it is outcompeted by salt meadow cordgrass in the high marsh. It grows in a wide range of salinities, from about 5 psu to marine (32 psu), and has been described as the "single most important marsh plant species in the estuary" of Chesapeake Bay. It is described as intolerant of shade.

S. alterniflorus is noted for its capacity to act as an environmental engineer. It grows out into the water at the seaward edge of a salt marsh, and accumulates sediment and enables other habitat-engineering species, such as mussels, to settle. This accumulation of sediment and other substrate-building species gradually builds up the level of the land at the seaward edge, and other, higher-marsh species move onto the new land. As the marsh accretes, S. alterniflorus moves still further out to form a new edge. S. alterniflorus grows in tallest forms at the outermost edge of a given marsh, displaying shorter morphologies up onto the landward side of the Sporobolus belt.

Petrified Forest National Park is a national park of the United States in Navajo and Apache counties in northeastern Arizona. Named for its large deposits of petrified wood, the park covers about 346 square miles (900 square kilometers), encompassing semi-desert shrub steppe as well as highly eroded and colorful badlands. The park's headquarters is about 26 miles (42 km) east of Holbrook along Interstate 40 (I-40), which parallels the BNSF Railway's Southern Transcon, the Puerco River, and historic U.S. Route 66, all crossing the park roughly east–west. The site, the northern part of which extends into the Painted Desert, was declared a national monument in 1906 and a national park in 1962. The park received 644,922 recreational visitors in 2018.

Averaging about 5,400 feet (1,600 m) in elevation, the park has a dry windy climate with temperatures that vary from summer highs of about 100 °F (38 °C) to winter lows well below freezing. More than 400 species of plants, dominated by grasses such as bunchgrass, blue grama, and sacaton, are found in the park. Fauna include larger animals such as pronghorns, coyotes, and bobcats; many smaller animals, such as deer mice, snakes, lizards, and seven kinds of amphibians; and more than 200 species of birds, some of which are permanent residents and many of which are migratory. About one third of the park is designated wilderness—50,260 acres (79 sq mi; 203 km).