Appearance

Spartina patens is a tufted perennial warm season grass, (family Poaceae) that grows from 1-4 ft. (0.25-1.22 m) in height. The rhizomatous roots help to spread this species. S. patens is native to the southeastern coast of North America and can be seen growing in brackish marshes, low dunes, sand flats, beaches and high salt marshes.

Foliage

The light green S. patens leaf blades are narrow ranging from 0.04-0.16 in. (1-4 mm) wide at the base with inrolled margins. The internode is firm and ligules are about 0.02 in. (0.5 mm) long. The leaves are deciduous, with new growth each year.

Flowers

The inflorescence is an open dark-colored panicle. Branches of the panicle are spreading to ascending with lower branches usually not overlapping. Panicles are generally about the same height as the foliage.

Fruit

S. patens reproduces both through seed and vegetative rhizomatous roots. Rhizomes are usually long and wiry ranging from 0.08-0.16 in. (2-4 mm) in diameter.

Ecological Threat

Estuarine habitats of the East coast and the West coast of the United States are physically different. The Spartina species, native to the east coast provide the appropriate food and shelter for the native wildlife in that area. However on the west coast, these same grasses cause many problems. They convert the much of the mudflats expected on the west coast to high marsh which has a negative effect on feeding areas, nesting areas, nursery areas, resting sites and shellfish production. In addition they are able to successfully compete against native vegetation, sometimes completely replacing it in the habitat.

Selected Images

Maps

Invasive Listing Sources

• California Invasive Plant Council
• California Noxious Weeds
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States

References