Flowering stems erect to procumbent, 15–35 cm × 1–2.5 mm, mostly branching proximal to middle. Sepals usually strongly maroon tinged, sometimes brown, outer sepals shorter than inner. Seeds 3–4(–5), weakly 3-sided or 2-sided and convex.

Flowering summer; fruiting late summer–fall. Coastal sands, pine barrens; 0–20 m; Conn., Del., Maine, Md., Mass., N.H., N.J., N.Y., R.I.

Disjunct populations from eastern Canada are treated here as var. subcylindrica.