Flora of North America species comparison

single, terete, 2.5–8(–10) dm, branching all or mostly alternate.

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.

basal and cauline usually present at flowering time;

basal blades oblanceolate to spatulate, 4–10 cm × 9–25 mm;

cauline blades abruptly differentiated, linear to lanceolate, 1.5–5(–6.5) cm × 1–8(–15) mm.

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.

flowers solitary or paired at ends of branches;

pedicels (30–)80–120 mm.

cymes of compact cymules;

pedicels 1–2(–4) mm.

8–12(–14)-merous;

calyx tube shallowly campanulate, (2–)3–4(–8) mm, mid- and commissural veins about equally prominent, not ridged;

lobes narrowly linear to subulate, 4–20 mm;

corolla pink or rarely white, eye yellow, projections of eye into corolla lobes oblong, usually with a red border, tube 5–9 mm, lobes narrowly spatulate-obovate, 16–35 × 5–12 mm, apex rounded to obtuse;

anthers coiling circinately.

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.

 = 36.

 = 32, 34.