Flora of North America species comparison

usually single, occasionally 2–several, 4-angled with wings 0.1–0.5 mm wide, 1.5–5(–7.5) dm, branching all opposite or secondary and/or tertiary occasionally alternate.

single, terete, 1.5–9(–11) dm, branching alternate.

basal and cauline or only cauline present at flowering time;

basal blades spatulate-obovate;

cauline blades linear-oblong to ovate-lanceolate, 0.8–2.5(–6) cm × 3–8(–18) mm.

all cauline at flowering time;

blade mostly linear, 1–5 cm × 0.5–2 mm or those near base to 5 mm wide, distal leaves filiform.

cymes of compact cymules;

pedicels 1–2(–4) mm.

open, few-flowered cymes or solitary flowers;

pedicels (20–)40–120 mm.

5-merous;

calyx tube widely obconic to campanulate, 1.5–3(–3.5) mm, mid- and commissural veins about equally prominent, low-ridged, lobes linear-subulate or rarely wider, 2–8(–11) mm;

corolla white throughout (sometimes drying yellow or salmon) or occasionally with a yellow eye, projections of eye into corolla lobes, when present, triangular, without a contrasting border, tube 2.5–7 mm, lobes oblanceolate to narrowly spatulate-obovate, 4.5–15 × 1.5–6 mm, apex rounded to obtuse;

anthers coiling circinately.

5-merous;

calyx tube campanulate, 6–25(–30) mm, midveins slightly more prominent than commissural veins, veins not ridged or midveins low-ridged, lobes subulate to linear;

corolla pink or occasionally white, eye yellow, projections of eye into corolla lobes oblong, usually with red border, tube 3–8 mm, lobes narrowly to medium-widely obovate, (13–)17–30 × 5–15 mm, apex rounded to subacute;

anthers coiling circinately.

 = 32, 34.

 = 36.