Flora of North America species comparison

single, terete, 1.5–7 dm, branching all or mostly alternate.

single, 4-angled with wings 0.2–0.3 mm wide, (0.5–)3–7.5(–9) dm, branching proximally mostly opposite, distally mostly alternate.

all cauline or basal occasionally persistent at flowering time;

blade linear to oblong-lanceolate, 0.5–3 cm × 1–5(–7) mm.

all cauline at flowering time or basal sometimes persistent;

basal blades oblong-spatulate to ovate-orbiculate;

cauline blades lanceolate to widely ovate, 1–4 cm × 5–30(–40) mm.

open cymes or solitary flowers at ends of branches;

pedicels (10–)20–40(–50) mm.

open cymes;

pedicels 10–60 mm.

5-merous;

calyx tube obconic, 1–3 mm, mid- and commissural veins about equally prominent, not or low-ridged, lobes filiform, 3–8 mm;

corolla white, eye greenish yellow, projections of eye into corolla lobes without a contrasting border, tube 1–3 mm, lobes oblanceolate, 6–18 × 2–7 mm, apex obtuse to acute;

anthers coiling circinately.

5(or 6)-merous;

calyx tube shallowly campanulate, 1–2 mm, mid- and commissural veins about equally prominent, low-ridged, lobes linear to narrowly oblong-lanceolate or occasionally ± foliaceous, 4–15(–18) mm;

corolla pink or occasionally white (sometimes drying orange), eye greenish yellow, projections of eye into corolla lobes triangular, usually with dark red border, tube 4–7 mm, lobes ± narrowly spatulate-obovate, 6–22 × 2–9(–11) mm, apex rounded to subacute;

anthers coiling circinately.

 = 32.

 = 38.