Flora of North America species comparison

erect or ascending at base, very rarely prostrate, unbranched to well branched, branches sometimes very slender, 15–75 cm, glabrous, with slightly raised lines decurrent from leaf axils.

prostrate or decumbent and ascending at tips, slightly ridged, often well branched, 5–70 cm, glabrate to sparsely strigillose, denser on distal parts.

alternate;

stipules reddish purple, narrowly ovate, 0.2–0.3 × 0.1–0.3 mm, succulent;

petiole winged, 0.3–1.2 cm, blade usually oblanceolate-spatulate to spatulate or oblanceolate, rarely sublinear, 1–2.5(–3) × 0.1–0.8 cm, base attenuate, margins subentire with hydathodal glands, apex acute or mucronate, surfaces glabrous;

bracts not reduced.

opposite;

stipules narrowly deltate or ovate, 0.05–0.15 × 0.05–0.1 mm; submerged stems: petiole 0–0.2 cm, blade narrowly linear, 1.9–4 ×0.1–0.25 cm;

emergent stems: petiole 0–0.2 cm, blade narrowly elliptic or narrowly oblanceolate-elliptic to linear, 0.6–1.8 × 0.2–0.5 cm, base narrowly cuneate, margins entire, apex acute, surfaces glabrous or sparingly strigillose on margins and abaxial midveins;

bracts reduced.

usually not congested, leafy racemes or spikes, flowers solitary in leaf axils;

bracteoles attached in opposite pairs near base of ovary, narrowly lanceolate, lanceolate-elliptic, or oblong-linear, 1.5–3.5(–4) × 0.4–0.8 mm, swollen at base, apex acuminate.

in racemes or spikes, well-formed on ascending stems, not on prostrate stems;

bracteoles attached at base of ovary or 1.5–8 mm proximally on pedicels, sublinear to very narrowly elliptic, 1.4–5 × 0.2–0.8 mm, apex acute, surfaces minutely strigillose.

sepals ascending, green fading to white near base, ovate-deltate, 1.5–3 × 1.2–2 mm, margins entire, apex narrowly acute or acuminate, surfaces glabrous;

petals 0(–3), narrowly elliptic or spatulate, 1–2.5 × 0.5–1 mm, base attenuate, apex obtuse;

filaments pale yellow, 0.8–1(–1.3) mm, anthers 0.3–0.6 × 0.3–0.5 mm;

pollen shed singly;

ovary obovate-obpyramidal, 2–2.5 × 1.8–2.3 mm, glabrous;

nectary disc elevated 0.3–0.4 mm on ovary apex, green, 0.9–1.6 mm diam., prominently 4-lobed, glabrous;

style pale green, 0.4–0.7 mm, glabrous, stigma pale yellow, subglobose, 0.3–0.4 × 0.2–0.4 mm, not exserted beyond anthers.

sepals reflexed or spreading, green, lanceolate-deltate, 5.2–10 ×1.5–2.7 mm, with 3 prominent parallel veins, margins entire and minutely strigillose, apex acute or elongate-acuminate, surfaces minutely strigillose abaxially;

petals rarely caducous, elliptic-obovate to spatulate-obovate, 7–11 × 4.5–8 mm, base attenuate, apex rounded;

filaments initially spreading, becoming erect, yellow, 2.5–4.5 mm, anthers 1.3–2 × 0.7–1.1 mm;

pollen shed in tight tetrads;

ovary cylindric to funnelform, 4–5.5 × 1.5–2.8 mm;

nectary disc elevated 0.6–1 mm on ovary apex, 1.5–2.6 mm diam., bright yellow, with 4 distinct domed lobes, minutely strigillose between lobes or glabrous;

style yellow, 2.3–4(–4.8) mm, glabrous, stigma yellow, broadly capitate, 0.3–0.6 × 0.6–1.8 mm, as long as or exserted beyond anthers.

obconic, obscurely 4-angled, (2–)2.5–4(–4.7) × 2–3(–3.5) mm, hard-walled, dehiscent by loculicidal slits, pedicel 0.1–0.5 mm.

clavate, subterete, sometimes slightly curved, 5.5–10 × 2.3–4 mm, hard-walled, irregularly dehiscent, pedicel (12–)17–45 mm.

light brown, ellipsoid, 0.4–0.6 × 0.3–0.4 mm, surface cells transversely elongate, glabrous or, sometimes, with surface wax that mimics appressed hairs.

light to dark brown, elliptic-oblong, 0.5–0.7 × 0.3–0.4 mm, surface cells transversely elongate.

= 64.

= 32.