Flora of North America species comparison

often branched, to 2.5 m. Turions absent.

often branched, to 3 m. Turions absent.

usually in whorls of 4(–6), often subverticillate, sometimes alternate, heteromorphic;

petiole to 5 mm; submersed leaves pectinate, ovate to obovate in outline, (6–)12–29(–65) × (12–)14–18(–50) mm, segments (10–)12–20(–28), linear-filiform, longest segment (7–)9–25(–29) mm; emersed leaves pectinate to pinnatifid proximally, lanceolate to ovate or elliptic distally, 3–14(–31) × 1–5(–7) mm, margins serrate to lobed.

mostly in whorls of (3 or)4(or 5), sometimes opposite to subopposite, heteromorphic;

petiole 0–4 mm; submersed leaves pectinate to lobed (basalmost leaves opposite to subopposite, reduced, margins entire), ovate to obovate in outline, (3–)5–25(–35) × (2–)3–18(–20) mm, segments (2 or)3–9(–11), linear, ± applanate, longest segment (7–)8–15(–17) mm; emersed leaves pinnatisect to lobed or entire, ovate to oblong in outline, 2–9 × 1–6 mm, margins dentate to minutely serrate.

to 60 cm;

flowers proximally pistillate, medially bisexual, distally staminate;

bracteoles cream, ovate to triangular or deltate, 0.6–1.1 ×0.3–0.9 mm, margins serrate to irregularly lobed.

to 8 cm;

flowers proximally pistillate, medially bisexual, distally staminate;

bracteoles cream, deltate, 0.5–1 × 0.2–0.6 mm, margins dentate to serrate, with glandular tip.

sepals cream, lanceolate to narrowly triangular, 0.5–0.8(–0.9) × 0.1–0.2 mm;

petals persistent, cream, elliptic to obovate, 1.4–3 × 0.7–1.3 mm;

stamens 4, filaments to 1.6 mm, anthers 1.3–2.2 × 0.3–0.7 mm.

sepals green to cream, ovate to deltate, (0.2–)0.3–0.5(–0.7) × (0.1–)0.2–0.4(–0.5) mm;

petals persistent, ± purple, oblong, 2–3 × 0.5–1.5 mm;

stamens 8, filaments to 0.6 mm, anthers 1.8–2.5 × 0.2–0.6 mm.

sepals cream, triangular, (0.1–)0.2–0.6 × 0.1–0.3(–0.4) mm;

petals caducous, cream, elliptic to obovate, 1.5–2(–3) × 0.8–1 mm;

pistils 0.8–1.7 mm, stigmas red to ± purple, to 0.4 mm.

sepals cream, deltate, 0.2–0.5 × 0.1–0.4 mm;

petals ± persistent, cream, ± cucullate, elliptic, 0.1–0.5 × 0.2–0.3 mm;

pistils 1.1–2.2 mm, stigmas cream to ± purple, to 0.6 mm.

ovoid to subglobose, deeply 4-lobed.

cylindric to oblong, 4-lobed.

tan to red-brown, cylindric to narrowly ovoid, 1–1.5 ×0.5–0.8 mm, transversely orbiculate to widely elliptic, abaxial surface bluntly 4-angled, rounded to slightly flattened, densely papillate, with 4 shallow, longitudinal ridges, ridges sometimes with inconspicuous, shallow wings proximally, ribs absent.

tan to olive-brown, cylindric to ovoid, 1.5–1.8 × 0.6–0.8 mm, transversely elliptic, abaxial surface rounded, smooth, sometimes with a shallow, longitudinal ridge, wings and ribs absent.

= 42.