Sporobolus michauxianus (Hitchc.) P. M. Peterson & Saarela

Foodplant / pathogen
ergot of Claviceps purpurea var. spartinae infects and damages live ovary of Spartina pectinata

Spartina pectinata Link, Jahrb. Gewachsk. P: 92. 1820
Spartina cynosuroides var. aureo-marginata Irving. Gard. Chron. III. 38: 372. 1905. (Type grown at Kew Gardens, received from New York Botanical Garden.)
Spartina Michauxiana Hitchc. Contr. U. S. Nat. Herb. 12: 153. 1908. (Based upon the plant described by Michaux as Trachynolia cynosuroides, but the name based on Dactylis cynosuroides L.)
Spartina Michauxiana var. Sultiei Farwell, Rep. Mich. Acad. 21: 352. 1920. (Type from Orchard Lake, Michigan, Sultie.)
Spartina Michauxiana var. tenuior Farwell, Rep. Mich. Acad. 21: 352. 1920. (Type from River Rouge, Michigan, [Farnell 513S.)
Spartina cynosuroides var. Michauxiana St. Yves, Candollea S: 58. 1932. (Based on 5. Michauxiana Hitchc.)
Spartina cynosuroides var. Michauxiana f. major St. Yves, Candollea 5: 61, 62. 1932. (Localities cited, Canada, Viclorin 11358; Victorin if Germain 9055; also Nova Scotia, Newfoundland. Massachusetts, Ohio, Illinois, Minnesota, and Missouri.)
Spartina cynosuroides X gracilis St. Yves, Candollea 5: 66. 1932. (Type from Oregon. Ballards Landing, Cusick 221 in 1890 [error for 2221 in 1899].)
Spartina peclinata var. Suitiei Fernald. Rhodora 35: 260. 1933. (Based on S. Michauxiana var. Suttiei Farwell.)
Culms 0.6-2 meters tall, erect from stout, widely spreading rhizomes; sheaths much longer than the internodes, rounded on the back or obscurely keeled at the summit, glabrous or more or less pubescent at the mouth and on the collar; Ugule ciliate, 1-3 mm. long; blades elongate, 5-12 mm. wide at the base, attenuate, glabrous on both surfaces, the margins very hispid; spikes 5-20 (rarely 30), appressed or narrowly ascending, the lower 5-12 cm. long, gradually shorter upward, the peduncles mostly 1-3 cm. long, the rachis hispid-cUiate on the margins; spikelets usually closely appressed; glumes conspicuously hispid on the keels, the first narrow, acuminate, awned, about as long as the lemma, the second much broader, its body a Httle longer than the lemma, pilose on the margins, the coarse scabrous awn 1-7 mm. long; lemma 7-9 mm long, hispid on the keel, otherwise glabrous, minutely lobed; palea exceeding the lemma, minutely lobed, scabrous toward the summit.
Type locality: North Carolina (Bosc).
Distribution: Fresh or brackish marshes, Newfoundland to Washington and Oregon, and southward to North Carolina, Texas, and New Mexico.

Perennials, Aquatic, leaves emergent, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stolons or runners present, Stems nodes swollen or brittle, Stems erect or asc ending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule a fringe of hairs, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branch es, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Rachis angular, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes keeled or winged, Glume surface hairy, villous or pilose, Glumes 1 nerved, Glumes 3 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 3 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex dentate, 2-fid, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well d eveloped, Palea membranous, hyaline, Palea longer than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Sporobolus michauxianus is a species of cordgrass known as prairie cordgrass, freshwater cordgrass, tall marshgrass, and sloughgrass. It is native to much of North America, including central and eastern Canada and most of the contiguous United States except for the southwestern and southeastern regions. Its distribution extends into Mexico. It is also present on other continents as an introduced species.