Flora of North America species comparison

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

1–many, clustered, terete or distally 4-ridged but not angled or winged, 1.5–6(–9) dm, branching all or 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;

blade narrowly lanceolate or oblong (proximal) to linear (all or distal), 1–4 cm × 1–7(–12) mm.

open cymes or solitary flowers at ends of branches;

pedicels (10–)20–40(–50) mm.

open, few-flowered cymes or solitary flowers at ends of branches;

pedicels (20–)40–70(–90) 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-merous;

calyx tube turbinate to shallowly campanulate, 1–3 mm, mid- and commissural veins about equally prominent, not or low-ridged, lobes setaceous to narrowly linear;

corolla pink or rarely white, eye yellow, projections of eye into corolla lobes oblong, usually with a red border, tube 2–6 mm, lobes oblanceolate, 6–24 × 3–9(–11) mm, apex obtuse;

anthers coiling circinately.

 = 32.

 = 34.