Eriochloa contracta Hitchc.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem nodes bearded or hairy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf bl ades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades more or less hairy, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Ligule a fringe of hairs, 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 branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, 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 ped icel glabrous, Glumes present, empty bracts, Glumes 1 clearly present, the other greatly reduced or absent, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glumes 3 nerved, Glumes 4-7 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma becoming indurate, enclosing palea and caryopsis, Lemma 5-7 nerved, Lemma body or surface hairy, Lemma rugose, with cross wrinkles, or roughened, Lemma apex truncate, rounded, or obtuse, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma margins inrolled, tightly covering palea and caryopsis, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea longer than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Eriochloa contracta is a species of grass known by the common name prairie cupgrass. It is native to the central United States and it is naturalized in areas to the east and west, where it is often a weed, especially in moist areas. This annual grass may grow up to a meter tall when erect or it may bend, rooting where nodes on the stem touch the ground. The inflorescence is up to 20 centimeters long and is made up of several branches which stick out to the sides. The branches are lined with purplish spikelets a few millimeters long.

Eriochloa contracta là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Hitchc. mô tả khoa học đầu tiên năm 1928.