Flora of North America species comparison

erect, sparsely to densely villous proximally, sometimes glabrous distally.

prostrate, decumbent, ascending, or erect, sometimes arching, creeping, sprawling, spreading, scrambling, pendent, climbing, or reclining, sometimes absent.

cauline, whorled, rarely opposite;

petiole present;

blade not fleshy, not leathery, margins serrate to doubly serrate.

deciduous or persistent, basal, basal and cauline, or cauline, opposite, subopposite, alternate, helical, or whorled, sometimes opposite proximally, alternate distally, simple;

stipules absent;

petiole present or absent;

blade fleshy or not, leathery or not, margins entire to subentire, toothed, or lobed.

terminal, spikelike racemes;

peduncle absent;

bracts present.

axillary or terminal, spikes, racemes, cymes, corymbs, thyrses, whorls, panicles, spiciform, or flowers 1–4.

present;

bracteoles present.

bisexual;

sepals (4 or)5, proximally connate, calyx bilaterally symmetric, cylindric, lobes lanceolate;

corolla white or pinkish, weakly bilaterally symmetric, weakly bilabiate, tubular-salverform, tube base not spurred or gibbous, lobes 4, abaxial 3, adaxial 1;

stamens 2, proximally adnate to corolla, filaments pubescent proximally;

staminode 0;

ovary 2-locular, placentation axile;

stigma capitate.

bisexual, rarely unisexual (Callitriche, Hippuris, Littorella), perianth and androecium hypogynous (epigynous in Hippuris);

sepals (2–)4 or 5, basally or proximally connate, sometimes distinct, rarely a minute rim (Hippuris) or 0 (Callitriche), calyx radially or bilaterally symmetric;

petals 0 (Callitriche, Hippuris) or (3 or)4 or 5, connate, corolla radially or bilaterally symmetric, ± bilabiate, bilabiate and personate, or regular, rarely unilabiate (Synthyris), ± rotate to salverform, ± cylindric, tubular, funnelform, urceolate, ellipsoid, globular, ovoid, or ligulate;

stamens (1 or)2–4 or 5, adnate to corolla or free, didynamous or equal, staminodes 0 or 1(–3);

pistil 1, 2-carpellate (1 in Hippuris), ovary superior (inferior in Hippuris), 2-locular, sometimes 1-locular or 4-locular (Callitriche), placentation axile, sometimes parietal (Dopatrium), parietal centrally and axile distally and proximally (Synthyris), apical (Hippuris), basal (Callitriche, Littorella), or free-central (Plantago);

ovules anatropous, hemitropous, hemianatropous, or campylotropous, unitegmic, tenuinucellate;

styles [0]1 (2 in Callitriche);

stigma 1 (2 in Callitriche).

capsules, dehiscence loculicidal, sometimes also septicidal, becoming 2- or apparently 4-valved distally.

capsules, dehiscence loculicidal, septicidal, or poricidal, or nutlets (Littorella), pyxides (Plantago), schizocarps (Callitriche), drupes (Hippuris), or drupelike (Lagotis).

10–30, brown or reddish brown, ellipsoid, wings absent.

1–300, white, tan, brown, yellow, gray, black, maroon, or red, ovoid to ellipsoid, cylindric, globular, oblong, conic, disciform, patelliform, or angled;

embryo straight, rarely curved, endosperm present.