Flora of North America species comparison

glabrous, sometimes scabrous, glaucous.

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

basal and cauline, sometimes basal absent or reduced, opposite, leathery, glabrous, rarely scabrous, glaucous;

basal and proximal cauline petiolate, sometimes short-petiolate (P. immanifestus, P. lentus);

cauline sessile, sometimes short-petiolate, blade obovate, ovate, spatulate, trullate, oblanceolate, lanceolate, oblong, elliptic, linear, or orbiculate, margins entire.

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.

continuous or interrupted, cylindric, sometimes secund, axis glabrous, rarely scabrous or glutinous, cymes 2 per node;

peduncles and pedicels ascending to erect.

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

calyx lobes: margins entire or erose, herbaceous or ± scarious, glabrous, rarely scabrous, glandular, glandular-pubescent, or glutinous;

corolla lavender to blue, violet, purple, or pink, rarely white or red, bilaterally symmetric, rarely nearly radially symmetric (P. cyathophorus), weakly, rarely strongly, bilabiate, not personate, tubular-funnelform, funnelform, or weakly ventricose, rarely tubular-salverform or weakly ampliate, glabrous externally, rarely obscurely glandular, glabrous or hairy internally abaxially, throat slightly to abruptly inflated, not constricted at orifice, rounded abaxially, rarely slightly 2-ridged;

stamens included to exserted, filaments glabrous, pollen sacs opposite, rarely divergent or parallel, navicular, rarely explanate (P. murrayanus), dehiscing completely, connective splitting, sides glabrous, sutures papillate, sometimes smooth;

staminode included to exserted, flattened distally, (0.2–)0.4–3 mm diam., tip recurved, rarely coiled or straight, distal 10–50(–70)% hairy, hairs to 2.5 mm, rarely glabrous;

style glabrous.

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

glabrous.

brown or dark brown, angled, angled-elongate, or disciform, 1.8–5.4 mm.

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.