American Sloughgrass

Annual. Culms tufted, erect, soft, 15–90 cm tall, 2–4-noded. Leaf sheaths glabrous, usually longer than internodes; leaf blades 5–20 cm, 3–10 mm wide, grayish green, scabrid or abaxial surface smooth, apex acute; ligule 3–8 mm. Inflorescence 10–30 cm; racemes erect or narrowly ascending, 1–4 cm. Spikelets orbicular-cuneate in outline, flattened, 2.5–3 mm, gray-green, floret 1(–2); glumes glabrous or hispid, slightly inflated, laterally compressed, veins prominent, linked by oblique transverse veinlets; lemma scaberulous, apex cuspidate-aristate. Anthers 0.4–1 mm. Caryopsis oblong, ca. 1.5 mm, with a tuft of hairs at apex. Fl. and fr. Apr–Oct. 2n = 14.

Anhui, Fujian, Gansu, Guizhou, Hebei, Heilongjiang, Hubei, Jiangsu, Jilin, Liaoning, Nei Mongol, Qinghai, Shandong, Sichuan, Xizang, Yunnan, Zhejiang [Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Russia; Europe, North America].

Riversides, swampy meadows, damp places; below 3700 m.

Beckmannia syzigachne (Steud.) Fernald, Rhodora 30: 27. 1928
Panicum syzigachne Steud. Flora 29; 19. 1846.
Beckmannia erucaeformis var. unijlora Scribn.; A. Gray, Man. ed. 6. 628. 1890. (Localities cited,
Iowa, Minnesota and westward.) Beckmannia erucaeformis var. baicalensis Kuznetzov, Bull. Angew. Bot. 6: 584. 1913. (Type from
Siberia.) B«fcmonMiotaica(enj>"jHult^n.Sv. Vet.Akad. Handl. III. S: 119. 1927. (BaseA on B. erucaeformis
var. baicalensis Kuznetzov.)
Annual; culms rather coarse, erect, 30-100 cm. tall, glabrous or scaberulous; sheaths usually longer than the internodes, rounded on the back, scaberulous; ligule thin, white, 3-5 mm. long; blades 8-20 cm. long, 3-10 mm. wide, flat, firm, scabrous, especially on the margins; panicle erect, 10-25 cm. long; the branches appressed, 1-5 cm. long, naked at the base; spikes 1-2 cm. long, loosely appressed; spikelets 1-flowered, 3 mm. long, the glumes transversely wrinkled, the acuminate apex of the lemma usually protruding.
Type locality: Japan.
Distribution; Wet ground, marshes, and ditches, Manitoba to Alaska, and southward to New York, Illinois, New Mexico, and California; also in Asia.

Annuals, Aquatic, leaves emergent, Terrestrial, not aquatic, Stems nodes swollen or brit tle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 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 and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, 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 branches, Inflorescence branches more than 10 to nu merous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet 3-10 mm wide, 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 equal or subequal, Glumes equal to or longer than adjacent lemma, Glumes keeled or winged, Glume rugose with transverse wrinkles, Glumes 3 nerved, Glume saccate, inflated, or flabellate, Lemma similar in texture to glumes, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2 -branched, Stigmas 2, Fruit - caryopsis.

Beckmannia syzigachne, the American sloughgrass, or slough grass, is an annual or short-lived perennial bunchgrass in the grass family, Poaceae, found in shallow marshes or sloughs.

Beckmannia syzigachne is widespread across much of Europe, Asia, and North America.

Beckmannia syzigachne is one of only two species in the genus Beckmannia; the other being Beckmannia eruciformis.