Flora of North America species comparison

erect, trigonous, multiribbed, rather stiff.

erect, slender, leafy-based, trigonous, several-ribbed.

spreading to erect, overtopped by culm;

blades narrowly linear, proximally flattened, 0.5–3 mm wide, apex tapering, trigonous.

spikelet clusters 1–3, turbinate to hemispheric, 1.5–3 cm wide; subtending leafy bracts mostly exceeded by distal compound.

terminal, solitary, headlike, dense, white, leafy-involucrate;

involucral bracts several, flaring to recurved, white from broadened base nearly to median, then green to tapered tip, longer bracts 13 cm × 2–7 mm.

pale brown to nearly white, fusiform, 4–5(–7) mm, apex narrowly acute;

fertile scales elliptic, 3.5–4 mm, apex narrowly acute, midrib excurrent as mucro.

white, ovoid, 5–7 mm, apex acute;

fertile scales many, boatshaped, sharply curvedkeeled, 3–4(–5) mm, apex acute or blunt.

perianth bristles (15–)18–20, reaching tubercle tip, retrorsely barbellate.

perianth absent.

1 per spikelet, 2.5–3.2 mm;

body brown with pale center, obovoid distal to short stipe, lenticular, 1.7–2.2 × 0.8–1.5, margins narrow, wirelike, flowing into tubercle edges;

tubercle flat, narrowly triangular-subulate, 0.8–1 mm.

several per spikelet, 1.5–1.7(–2) mm;

body yellow to mahogany, broadly pyriformobovoid, tumidly lenticular, 1 × 0.5–0.7 mm, widest at apex, margins thickened, interrupted at base of tubercle;

surfaces transversely undulaterugose, ridges contiguous, of shortlinear papillae;

tubercle broadly triangular, 0.5–0.6 mm, graycrustaceous, apex short acuminate.

leaves overtopped by culm;

blades narrowly linear, proximally flat, (1.5–)2–3.5 mm wide, apex tapering, trigonous.

= 12.