Flora of North America species comparison

present.

absent.

compressed, without spots, 10–35 cm;

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 or floating absent, ± 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).

petiolate;

petioles continuous in color to apex, 0.7–0.8 cm;

blade adaxially light green, obovate to elliptic, 0.8–1.6 cm × 3–8.5 mm, base acute, apex round to acute;

veins 3–7.

sessile, lax;

stipules persistent to deliquescent, inconspicuous, convolute, adnate to blade ½ stipule length, light brown to red-brown, ligulate, 1.5–2.3 cm, not fibrous, not shredding at tip, apex obtuse;

blade red-brown to light green, linear, often arcuate, 1–1.3 cm × 0.1 mm, base slightly tapering, without basal lobes, not clasping, margins entire, not crispate, apex not hoodlike, acute, lacunae present, 1–2 rows each side midrib;

veins 1.

unbranched;

peduncles dimorphic, submersed axillary, recurved, clavate, 3–5 mm, emersed axillary or terminal, erect to slightly recurved, clavate, 6–15 mm;

spikes dimorphic, submersed capitate, 2–3 mm, emersed cylindric, 5–9.7 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, greenish brown, orbicular, compressed, abaxially winged, laterally winged, 1–1.5 × 0.9–2 mm, lateral wings with sharp points;

beak present, erect, 0.1 mm;

sides without basal tubercles;

embryo with more than 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.