Flora of North America species comparison

present or absent, if present, erect, glabrous or hairy.

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

usually basal, usually alternate, (cauline and opposite in P. afra, P. indica, P. sempervirens);

petiole absent or present;

blade fleshy, leathery or not, margins entire or toothed.

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.

erect or ascending, rarely decumbent (P. coronopus), surpassing leaves, sometimes slightly so (P. tweedyi) or not (P. major).

axillary, spikes or spiciform, dull, sometimes shiny (P. canescens, P. lanceolata, P. media);

bracts present.

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

absent or present;

bracteoles absent.

bisexual;

sepals 3 or 4, nearly distinct (abaxials connate in P. lanceolata), oblong, calyx radially, rarely bilaterally, symmetric, cuplike;

corolla semitransparent, radially or weakly bilaterally symmetric, lateral lobes smaller, ± tubular to ± funnelform, tube base not spurred or gibbous, tube glabrous, rarely hairy (P. coronopus, P. maritima), lobes 4;

stamens 2 or 4, free, equal, filaments glabrous;

staminode 0;

ovary 2-locular, placentation free-central, sometimes axile;

stigma elongate.

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).

pyxides, lanceoloid, rarely ovoid (P. macrocarpa), dehiscence circumscissile (indehiscent or dehiscence not circumscissile in P. macrocarpa).

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

(1 or)2–35, black or brown, sometimes dark red (P. rhodosperma) or yellowish brown (P. virginica), oblong, 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.