Flora of North America species comparison

present.

absent.

compressed, without spots, 10–35 cm;

glands absent.

flattened, without spots, to 100 cm;

nodal glands absent.

absent.

common, axillary or terminal, 1.5–3 × ca. 2 cm, hard;

leaves ± 2-ranked;

outer leaves 1–4 per side, base not corrugate, apex rounded;

inner leaves rolled into linear, terete structure, oriented parallel to outer leaves.

both submersed and floating or floating absent, ± spirally arranged.

submersed, ± spirally arranged, sessile, lax;

stipules persistent to deliquescent, inconspicuous, convolute, free from blade, brownish, not ligulate, to 0.5 cm, not fibrous, not shredding at tip, apex obtuse;

blade light to dark green, linear, not arcuate, 1.2–9 cm × 4–10 mm, base obtuse to rounded, without basal lobes, not clasping to nearly clasping, margins conspicuously serrate, not crispate, apex not hoodlike, round to round-acute, lacunae in 2–5 rows each side of midrib;

veins 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, terminal or rarely axillary, erect to ascending, cylindric, 2.5–4 cm;

spikes not dimorphic, cylindric, 10–15 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.

sessile, red to reddish brown, obovoid, turgid to slightly concave, not abaxially or laterally keeled, 6 × 2.5 mm;

beak apically recurved, 2–3 mm;

sides without basal tubercles;

embryo with 1 full spiral.

= 52 (Europe).