Flora of North America species comparison

single, terete or slightly 4-ridged but not angled or winged, 1.5–4.5(–7) dm, branching opposite or alternate.

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

basal and cauline present at flowering time;

blade oblong to elliptic, 2–5(–7) cm × 7–20(–25) 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.

heads, sessile.

open, few-flowered cymes or solitary flowers;

pedicels (20–)40–120 mm.

7–12-merous;

calyx tube widely campanulate, 3–6 mm, not ridged, lobes linear, 4–10 mm;

corolla pink or rarely white, eye pale yellow, projections of eye into corolla lobes semicircular, without a contrasting border, tube 5–7 mm, lobes narrowly spatulate-obovate, 12–25 × 5–13 mm, apex rounded;

anthers remaining straight or nearly so, not coiling.

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.

 = 76.

 = 36.