OregonFlora species comparison

terete, 30–90 cm; nodal glands absent.

terete to slightly compressed, 18– 150 cm; nodal glands present on at least some nodes; to 0.5 mm diameter, green; gold, brown, or rarely white.

submersed and floating.

submersed, attached to stem nodes, not attached to stipules;

stipules convolute, 3.1–9.2 mm, rarely fibrous;

tip acute to obtuse;

blades linear, 9–54 × 0.2–2.5 mm;

base slightly tapering;

margins entire;

tip subulate to obtuse; lacunae in 1–5 rows on each side of midrib;

veins 1–3(5).

elliptic to ovate, 35–110 × 15–60 mm;

base rounded to cordate;

tip acute to rounded;

veins 17–37;

petioles 55–290 mm.

sessile, attached to stem nodes, not attached to stipules;

stipules 45–100 mm; whitish, fibrous;

tip obtuse;

blades rigid, linear, subterete, 9–20 cm × 0.7–2.5 mm;

base slightly tapering;

margins entire;

tip obtuse;

veins 3–5, obscure.

emersed;

spikes cylindric, 25–50 mm;

peduncles terminal; erect to ascending, 45–95 mm.

submersed or emersed;

spikes capitate to cylindric, continuous to interrupted, 1.5–10.1 mm;

peduncles more than 3 per plant; axillary or terminal, cylindric to slightly clavate; erect, rarely recurved, 5–66 mm.

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

beaks erect to apically recurved, 0.4–0.8 mm.

sessile; ovoid;

sides rounded, rarely concave, 1.5–2.2 × 1.2–1.6 mm, green to brown, not keeled;

beaks erect, located at middle of fruit tip, 0.1–0.6 mm.