Flora of North America species comparison

present.

absent.

terete, often rust-spotted, 30–90 cm;

nodal glands absent.

slightly compressed, without spots, 4–75 cm;

glands rarely present, black to gold, to 0.5 mm diam.

absent.

uncommon, lateral or terminal, 0.9–2.5 cm × 0.6–2 mm, soft;

outer leaves 1–3 per side, base not corrugate, apex acute to apiculate;

inner leaves rolled into hardened fusiform structure.

both submersed and floating, ± spirally arranged.

submersed, ± spirally arranged, sessile, delicate;

stipules persistent, inconspicuous, convolute, free from blade, greenish to brown or rarely white, not ligulate, 0.2–2.2 cm, delicate to fibrous, rarely shredding at tip, apex obtuse;

blade pale green to olive-green, rarely somewhat reddish, linear, not arcuate, 1.3–8.2 cm × 0.3–2.3 mm, base slightly tapering, without basal lobes, not clasping, margins entire, not crispate, apex not hoodlike, acute to apiculate, rarely with bristle, lacunae rarely present, 0–2 rows each side of midrib;

veins 1–3(–5).

petioles lighter green immediately proximal to apex, 5.5–29 cm;

blade adaxially light green, elliptic to ovate, 3.5–11 cm × 15–60 mm, base cordate, apex acute to rounded;

veins 17–37.

sessile, rigid;

stipules persistent, conspicuous, convolute, free from blade, whitish, not ligulate, 4.5–1 cm, fibrous, not shredding at tip, apex obtuse;

blade light to dark green, phyllodial, not arcuate, 9–20 cm × 0.7–2.5 mm, base slightly tapering, without basal lobes, not clasping, margins entire, not crispate, apex not hoodlike, obtuse, lacunae absent;

veins 3–5, obscure.

unbranched, emersed;

peduncles not dimorphic, terminal, erect to ascending, cylindric, 4.5–9.5 cm;

spikes not dimorphic, cylindric, 25–50 mm.

unbranched, emersed;

peduncles not dimorphic, in axils of proximal, rarely distal leaves, recurved, clavate, 0.3–1.1(–3.7) cm;

spikes not dimorphic, capitate to cylindric, 1.5–7 mm.

sessile, green to greenish brown, obovoid, turgid, not abaxially or laterally keeled, 3.5–5 × 2–3 mm;

beak erect to apically recurved, 0.4–0.8 mm;

sides without basal tubercles;

embryo with 1 full spiral.

pale green to olive-green or brown, obovate to nearly orbicular, turgid to concave, sessile, abaxially keeled, not laterally keeled, 1.4–2.7 × 1.1–2.2 mm, abaxial keel undulate, winglike;

beak erect, 0.2–0.6 mm;

sides without basal tubercles;

embryo with 1 full spiral.

= 52.