Flora of North America species comparison

frequently creeping and rooting at nodes, procumbent, decumbent, or weakly erect, often branched near base.

from creeping rhizome, erect or decumbent, much-branched distally.

opposite;

sessile;

blade spatulate or oblong to broadly obovate or orbiculate, 5–15 × 3–8 mm, base narrowly attenuate.

mostly alternate;

sessile or subsessile;

blade (on main stem) oblong to suborbiculate, 15–25 × 6–15 mm, mostly longer than internodes and closely overlapping distally, (on branches) oblong to linear, 6–10 × 1–2 mm, base attenuate.

spikelike.

racemes.

opposite or alternate, along most of stem, sessile to subsessile, monostylous;

floral tube broadly campanulate, 1 × 1.5 mm;

epicalyx segments equal to or to 2 times longer than sepals;

sepals 1/3–1/2 floral tube length, apex dark red;

petals early caducous, 0 or 6, white to pink or rose, 1 × 0.7 mm;

nectary absent;

stamens 6.

alternate, subsessile, pedicel slender, distylous;

floral tube without red spots, obconic, becoming cylindrical, 3.5–6 × 1.3–3 mm;

epicalyx segments 2 times length of sepals;

petals pale purple to purple, sometimes with red midveins, obovate, 3–5.5 × 1.5–5.5 mm, about as long as floral tube;

nectary encircling base of ovary, very narrow;

stamens 6.

surpassing floral tube, indehiscent, splitting irregularly.

septicidal or septifragal.

ca. 10–25, subglobose.

ca. 25, obovoid to fusiform.

= 10 (Europe).

= 20.