Flora of North America species comparison

slender to ± stout, especially proximally.

usually branched proximally, 10–50+ cm.

spreading or ascending to erect, simple or branched, terete to somewhat angular.

blades usually appearing terete, 1.5–3(–5) cm, margins often revolute, forming abaxial channel.

opposite but appearing whorled, as 8–15 per axillary cluster, 2 clusters per node, connate proximally by often-prominent ridge from which stipules arise, sessile;

stipules 4 per node, white, ovate to triangular, margins entire but splitting variously with age, apex obtuse to acuminate;

blade 1-veined, linear or filiform, sometimes succulent, apex blunt to apiculate.

terminal, open to diffuse cymes;

bracts paired, minute.

erect to ascending, reflexed, secund in fruit.

erect to ascending, spreading or usually reflexed and sometimes secund in fruit.

sepals 3.5–5 mm;

petals ovate, 3/4–1 times as long as sepals in flower, apex obtuse;

stamens usually 10.

usually bisexual, sometimes pistillate by stamen abortion;

perianth and androecium briefly perigynous;

hypanthium dish- or cup-shaped, not abruptly expanded distally;

sepals distinct, silvery, elliptic to nearly ovate, 2.5–5 mm, herbaceous, margins scarious, apex acute to obtuse;

petals 5, white, blade apex entire;

nectaries at adaxial base of broader filaments opposite sepals;

stamens 5 and opposite sepals, or 10 and arising from distally tapered rim of hypanthium;

filaments distinct;

styles 5, distinct, filiform, 0.4–0.6 mm, glabrous proximally;

stigmas 5, linear along adaxial surface of styles, obscurely papillate (30x).

valves 3.5–5 mm.

ovoid, opening by 5 spreading to somewhat recurved valves;

carpophore absent.

sometimes keeled or winged, subglobose, 1–1.1 mm wide, surface minutely roughened or obscurely low-tuberculate (50x), covered with white, club-shaped papillae in part or throughout (packing of seeds in capsule may prevent papillae development in spots), wings white, ± 0.1 mm wide.

5–25, blackish, circular, subglobose or lenticular and laterally compressed, nearly smooth or finely papillate, membranous, entire marginal wing often present, appendage absent;

embryo peripheral, annular to spirally curved.

= 9.

= 18, 36 (both Europe).