Scientific Name
Spartina gracilis Trin. (Synonyms: Sporobolus hookerianus)
Common Name(s)
Alkali cordgrass
Tribe / Family Name
Cynodonteae
Flowering Period
July to October
Symbol
SPGR
Description
Alkali cordgrass is a native warm-season perennial rhizomatous grass that reproduces from seeds, rhizomes, and tillers. Culms range from 40–100 cm in height. Its inflorescence is a panicle that is usually 8–25 cm long with 3–12 racemosely arranged unilateral branches with 18–28 appressed spikelets. Spikelets are 6–11 mm long, ovate to lanceolate, sessile, strongly compressed, closely crowded, and 1-flowered; disarticulation below the glumes. Glumes are acute or mucronate, and unequal (lower glumes usually 3.5–5 mm long, linear, keels glabrous or strigose along the keel, 1-nerved; upper glumes usually 7–8.5 mm long, narrowly lanceolate, usually equaling the florets, keels strigose along the keel, 3- to 5-nerved). Lemmas are 5.5–8.5 mm long, lanceolate, ciliate along the keels (at least towards the tips), 3-nerved, and usually blunt tipped. Awns are absent or mucronate, especially on the glumes. Sheaths are open and smooth to striate; throats sometimes ciliate. Auricles are absent. Ligules are a fringe of hairs 0.5–1.5 mm long. Blades are 6–30 cm long, up to 8 mm wide, flat, becoming involute when dried, scabrous along the edges, scabrous on the upper surface, and glabrous on the lower surface.
General Info
Alkali cordgrass can be found in alkaline or saline sites, wet meadows, moist seeps, along shores of lakes, streambanks, marshes, foothills, and plains.
Similar Species
Alkali cordgrass may look similar to prairie cordgrass (Spartina pectinata). To differentiate the two, check the glumes for awns. Alkali cordgrass has glumes that are awnless or mucronate, and prairie cordgrass has glumes that are awned.
Picture of growth habit.
Inflorescence is a panicle with 3-12 racemosely arranged, appressed spikes.
Close-up picture of spikelet.
Close-up picture of hairy ligule.
Illustration of alkali cordgrass. USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. <i>An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols.</i> Charles Scribner's Sons, New York. Vol. 1: 224.