Flora of North America species comparison

erect or ascending to creeping or floating, terete or sometimes angled distally, 20–300(–450) cm, usually densely branched, sometimes simple, glabrous if floating, or densely villous and viscid throughout, or rarely just on inflorescence.

erect, slightly ridged, unbranched or slightly branched, (16–)30–90 cm, glabrous or strigillose to hirtellous, especially on distal parts.

stipules (rarely in clusters of 3), ovate-deltate, 0.6–2 × 0.6–1.5 mm, fleshy, apex subacute, often mucronate;

petiole 0.1–1.1 cm;

blade usually lanceolate to (narrowly) elliptic or oblanceolate, rarely narrowly obovate, (1.7–)3.1–8(–10.5) × 0.5–2(–2.5) cm, chartaceous, viscid, base cuneate or attenuate, margins entire, apex obtuse or acute, always glandular-mucronate, surfaces densely villous, sometimes less dense adaxially, distal leaves more pubescent than proximal ones;

bracts scarcely reduced.

alternate;

stipules deltate, 0.25–0.45 × 0.15–0.4 mm;

rhizomes: sessile, blades minute, appressed, and scalelike, oblate or suborbiculate, 0.3–0.6 × 0.6–0.9 mm;

stolons: petiole 0.1–0.6 cm, blade oblong or oblanceolate-elliptic to spatulate, 0.4–3.5 × 0.2–1.5 cm;

main stem: sessile, blade lanceolate-elliptic or lanceolate-linear to linear, 2.5–9.5 × (0.1–)0.3–0.9 cm, proximal ones shorter and often oblong or oblong-lanceolate, base rounded or obtuse, margins entire with obscure hydathodal glands, apex acuminate to acute, surfaces glabrous or, sometimes, pilose on proximal blades;

bracts very reduced.

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

bracteoles narrowly to broadly obovate, 1–1.2 × 0.7–0.8 mm, succulent, apex acute, oppositely attached at ovary base.

densely clustered, terminal racemes or spikes, 1–5(–12) cm;

bracteoles attached at base of ovary or on pedicel distally, narrowly lanceolate, 3.5–5(–6) × (1.2–)1.4–2 mm, surfaces usually glabrous, sometimes pilose abaxially.

sepals usually deciduous, not persistent on capsule, lanceolate, 6–12(–16) × 2–4 mm, chartaceous, apex acute, surfaces densely villous;

petals yellow, fan-shaped, (12–)16–20(–26) × 11–16(–21) mm, apex rounded, usually emarginate, rarely mucronate;

stamens 10(or 12), in 2 unequal series, yellow, filaments reflexed, shorter ones (2.8–)3.8–5.3 mm, longer ones (3.7–)6–6.5 mm, anthers oblong, 1–2.5 × (0.6–)0.8–1.2 mm;

ovary subcylindric, terete, 6–12 × 1.5–2.5 mm, apex thickened, densely villous;

nectary disc slightly raised on ovary apex, yellow, 1.5–2.5 mm diam., lobed, ringed with villous hairs;

style yellow, 4.7–6.7(–8) mm, glabrous or sparsely pubescent near base, stigma subcapitate-globose, 1–1.3 × 1.6–2.5 mm, usually exserted beyond anthers.

sepals ascending, pale green or white adaxially, broadly ovate-deltate, 2.3–3.5(–4) × 2.3–3.2(–3.8) mm, margins entire, apex acuminate, surfaces glabrous;

petals 0;

filaments yellow or cream, 1.2–2 mm, distinctly dilated toward base, anthers 0.7–1(–1.3) × 0.5–0.7 mm;

pollen shed in tetrads;

ovary broadly obovoid or cup-shaped, 2.2–3 × 2.3–3.3 mm;

nectary disc elevated 0.5–0.6 mm on ovary apex, pale yellow, 1.8–3.1 mm diam., obscurely 4-lobed, glabrous;

style pale yellow, 0.9–1.7 mm, glabrous, stigma pale green to white, globose to capitate, 0.4–0.8 × 0.5–0.8 mm, distinctly 4-lobed, not exserted beyond anthers.

subcylindric, terete, straight or curved, (11–)14–25 × 3–4 mm, with thick woody walls, irregularly and tardily dehiscent, villous-viscid, pedicel 13–25(–27) mm.

broadly obpyramidal, angles rounded, sometimes subspherical, 2.5–4.3 ×2.5–4.5(–5) mm, hard-walled, dehiscent by apical ring, pedicel 0.5–1.5(–2) mm.

embedded in wedge-shaped piece of endocarp, 0.8–1 × 0.8–0.9 mm.

brown, elliptic-oblong, curved on both ends, 0.5–0.6 × 0.2–0.3 mm, surface cells ± isodiametric.

= 48.

= 32.