Flora of North America species comparison

1–15, trigonous, 7–30 cm × 1.2–2.5 mm, soft (flattened in pressing), glabrous.

to 25 cm apart, 1(–3) together, terete (scarcely compressed in drying), occasionally trigonous for apical 1/3, 40–140(–200) cm, 4–12 mm thick at base, (1.2–)1.5–2.5 mm thick at apex (with conspicuous transverse septa ca. 3 cm apart basally, to 3–5 mm apart apically), glabrous or infrequently scabrid on angles apically;

sheaths at base of culm, 2–3, (5–)10–25 cm, loose, papery.

2–7, flat, (2–)7–22 cm × 2.2–4 mm.

usually bladeless, blades when present, cross ribs prominent, especially adaxially, (1–)10–20(–40) cm × 4–6(–9) mm.

heads dense, 7–17 mm diam.; when rays short, heads sessile or nearly so, then densely irregularly lobate, 12–35 mm diam.;

rays 1–5, 2–32 mm;

bracts 2–4, longest bract erect or nearly so, appearing as continuation of culm, other bracts horizontal to ascending, 1–22 cm × 0.5–3.5 mm, margins and keel minutely scabridulous.

spikes 1(–5), broadly ovoid to ± umbellate, 15–45 × 10–30 mm;

rays 5–7(–10), 0.3–8(–12) cm; 2d order rays occasionally present, 5–20 mm;

bracts 2(–4), erect, longest appearing to be continuation of culm, deltate to lance-linear, 0.2–2(–9) cm × 1.5–4.5 mm;

rachilla persistent, wings translucent, whitish, or stramineous, 0.4 mm wide.

30–120, greenish brown to purplish brown, oblong-ellipsoid, compressed, (2–)3–5(–6) × 0.8–1.2 mm;

floral scales (6–)12–20(–30), laterally clear margins, stramineous to deep purple, medially greenish, stramineous, or purplish, laterally ribless, medially 3-ribbed, obovate to orbiculate, 0.6–0.8 × 0.6–0.8 mm, apex mucronulate.

(1–)5–10, linear, compressed, 10–35(–45) × 1.1–2 mm;

floral scales deciduous, 15–45, spreading or appressed, laterally light brown, medially green to brown, laterally 1–2-ribbed, medially 3-ribbed, oblong-elliptic to ovate, 2.9–3.7 × 1.1–1.6(–1.8) mm, apex acute.

stamens 1 or 2;

anthers ovoid-ellipsoid, 0.1 mm, connective not prolonged;

styles 0.1 mm;

stigmas 0.1–0.3 mm.

anthers 1.7–2.4 mm;

styles 1.2–3.6 mm;

stigmas 1.7–6 mm.

light brown, obovoid-ellipsoid, 0.6–0.8 × 0.3–0.4 mm (as long as subtending scale), base cuneate, apex obtuse, apiculate, surfaces finely reticulate, papillose.

brown, stipitate, obovoid-ellipsoid, 1.2–1.6 × 0.4–0.6 mm, stipe 0.1 mm, apex markedly apiculate, surfaces puncticulate.