Flora of North America species comparison

floating or creeping and ascending to erect, terete, 20–200(–400) cm, simple to densely branched apically, glabrous (floating) or sparsely to densely villous (emergent), sometimes villous only on inflorescence.

erect or somewhat sprawling, slightly to distinctly winged (wings to 1.8 mm wide), branched distally, 40–120(–160) cm, glabrous.

stipules ovate or deltate, 0.7–2 × 0.5–1.1 mm, not succulent, apex subacute, mucronate;

petiole flattened, 0.5–2(–2.5) cm;

blade narrowly oblanceolate, narrowly elliptic, or lanceolate to obovate or spatulate, (1.5–)4.2–10.7(–13.5) × (0.5–)0.8–3 cm, chartaceous, base cuneate or attenuate, margins entire, apex acute to obtuse, rounded or truncate, sometimes mucronate, surfaces not shiny, usually glabrous, sometimes villous on petiole and veins or throughout;

bracts not reduced.

alternate;

stipules ovate-deltate, often narrowly so, 0.2–0.4 × 0.1–0.3 mm, succulent;

stolons: petiole 0.15–1 cm, blades orbiculate to oblanceolate or broadly elliptic, 0.4–2.6 × 0.4–1.5 cm, base attenuate, apex rounded to subacute;

stems: petiole 0–0.3 cm, blade lanceolate-elliptic or very narrowly elliptic to linear, sometimes to oblanceolate or oblanceolate-elliptic near base, 1.8–10 × 0.2–1.3(–2) cm, base narrowly cuneate or attenuate, margins subentire with remote hydathodal glands, rarely minutely papillose-serrulate near apex, apex acute to narrowly acute, leaves on side branches much reduced;

bracts much reduced.

emergent stems sometimes in leafy racemes, sometimes reflexed, flowers solitary in leaf axils;

bracteoles obovate to narrowly obovate, 1–1.8 × 0.7–0.8 mm, apex acute or acuminate, attached on distal 1/2 of pedicel or at ovary base.

sometimes congested, leafy spikes or racemes, flowers solitary in distal leaf axils;

bracteoles attached near base of ovary, lanceolate-elliptic or narrowly so, 2.4–4.7 × 0.6–1.5 mm, margins minutely papillose or smooth, apex acute, surfaces glabrous.

sepals ovate-deltate or lanceolate-deltate, (8–)12–19 × 2–5 mm, chartaceous, margins entire, apex acuminate, surfaces ± densely villous;

petals bright yellow, sometimes with orange base, fan-shaped, (15–)20–30 × (12–)16–25 mm, apex emarginate or mucronate;

stamens 10(or 12), in 2 unequal series, yellow, filaments recurved, shorter ones (1.6–)2.3–5.2 mm, longer ones (3.1–)3.6–7.5 mm, anthers oblong, (1.2–)1.7–4 × 1–1.5 mm;

ovary subcylindric, terete, 10–18 × 2–3 mm, apex ± broadened, glabrous or sparsely to densely villous;

nectary disc slightly raised on ovary apex, yellowish green, 2–4 mm diam., lobed, glabrous or ringed with white hairs;

style yellow, 6–10 mm, glabrous, stigma subcapitate-globose, 0.5–1.5 × 1.5–2.5 mm, often exserted beyond anthers.

sepals spreading to reflexed, creamy white adaxially, broadly ovate-deltate, 2–4 × 1.6–4 mm, margins smooth or minutely papillose-serrulate, apex acute or acuminate, surfaces glabrous;

petals 0;

filaments nearly translucent, 1.1–1.7 mm, slightly dilated near base, anthers 0.5–0.9 × 0.4–0.7 mm;

pollen shed singly;

ovary obpyramidal, sharply 4-angled, 2–3.8 × 2–3.5 mm;

nectary disc elevated 0.5–0.8 mm on ovary apex, bright yellow, square with rounded corners, 2–3.3 mm diam., prominently 4-lobed, glabrous;

style pale green, 0.8–1.3 mm, glabrous, stigma pale yellow, subglobose, 0.3–0.6 × 0.3–0.7 mm, shallowly 4-lobed on top, not exserted beyond anthers.

cylindric or subclavate, terete, sometimes curved, (12–)16–24(–30)× 2.5–4 mm, with thick woody walls, irregularly and tardily dehiscent, pedicel (9–)13–25(–85) mm.

obpyramidal, sharply 4-angled and 4-winged, 3–5 × 2.8–4.5 mm, with hard walls somewhat bulging, dehiscent by apical ring, pedicel 0–0.8 mm.

embedded in wedge-shaped piece of endocarp, 0.8–1 × 0.8–1 mm.

light brown, ellipsoid, slightly curved on both ends, 0.6–0.7 × 0.3–0.4 mm, surface cells elongate transversely to seed length.

= 80.

= 48.