Mem. Torrey Bot. Club 5: 255. 1894.
Leaves all in basal rosettes, living at anthesis, 5–25(–40) cm; petiole often narrowly winged distally, 0.1–20 cm, usually shorter than blade; blade usually elliptic, spatulate, or obovate to oblanceolate (rarely linear), 5–15(–30) × 0.5–5(–7.5) cm, leathery, base gradually tapered, margins usually entire, sometimes undulate, apex rounded or acute to retuse, cuspidate, cusp 1–3 mm, soon falling; main lateral veins ascending, obscurely pinnate. Inflorescences: axes not winged, 10–60(–95) cm × 1–5 mm, glabrous; nonflowering branchlets absent; spikelets loosely to moderately densely aggregated along branches, internodes 0.5–10 mm; subtending bracts 2–6 mm, obtuse, surfaces and margins glabrous; flowers solitary or 2–3(–5) per spikelet. Flowers: calyx whitish, obconic, 4–6.5(–7.5) mm; tube 2.5–5 mm, glabrous or densely pilose along ribs; lobes erect, to ca. 2 × 1 mm; petals lavender (rarely white), slightly exceeding calyx. Utricles 3–5.5 mm. 2n = 36.
Phenology: Flowering Jun–Dec.
Habitat: Salt marshes and salt flats along Atlantic and Gulf seacoasts
Elevation: 0 m
N.B., Nfld. and Labr. (Nfld.), N.S., P.E.I., Que., Ala., Conn., Del., Fla., Ga., La., Maine, Md., Mass., Miss., N.H., N.J., N.Y., N.C., R.I., S.C., Tex., Va., Mexico (Tamaulipas), Bermuda.
J. L. Luteyn (1976, 1990) discussed the more or less continuous variation in this polymorphic species. He noted that seedling establishment is rare, and that populations spread primarily by vegetative means from horizontal rhizomes.