Flora of North America species comparison

erect, simple or few-branched, (7–)9–21(–29) cm, glabrous or glabrate proximally, glabrate or glandular-puberulent distally.

decumbent, ascending, or erect, simple, sometimes few-branched, (8–)15–60 cm, sparsely to densely glandular-puberulent or glandular-pubescent proximally, glandular-puberulent distally.

dimorphic, submersed basal and clustered, floating paired at ends of branches to 70 mm, blade of submersed lanceolate to oblanceolate or oblong, 1–7 × 0.5–3 mm, margins entire, apex obtuse to acute, surfaces glabrous, blade of floating elliptic to ovate or nearly round, 3–10 × 2–9 mm, margins entire, apex obtuse to rounded or retuse, surfaces glabrous.

blade lanceolate-ovate to ovate or oblong, rarely linear-lanceolate in submersed forms, 5–28 × 4–15 mm, margins with (3–)5–10(–12) pairs of sharp teeth, apex acute, rarely obtuse, surfaces sparsely to densely glandular-puberulent.

stout, 0.1–3 mm, length less than 0.1 times bract, glabrous;

bracteoles 0.

slender, 10–23 mm, length 0.5–2 times bract, sparsely to densely glandular-puberulent;

bracteoles 2, 3.5–7 mm.

sepals connate proximally, calyx lobes obovate to oblong, 0.7–1 mm;

corolla 3–4 mm, tube and limb white tinged pink or purple, veins lavender or purple;

style 0.5–1 mm.

sepals distinct, lanceolate to elliptic or ovate-lanceolate, 3–7 mm;

corolla 9–13 mm, tube yellowish brown, veins blue or lavender, limb white;

style 3–4 mm.

bilaterally symmetric, obcordiform, 2–3 × 3–4 mm.

globular, 1–2.5 × 1–2.5 mm.

(0.3–)0.4–0.5 mm.

0.3–0.4 mm.

= 18.

= 16.