Flora of North America species comparison

1–several, clustered, terete or distally 4-ridged but not angled or winged, 0.8–6 dm, branching all or mostly alternate.

4-angled with wings to 0.2 mm wide, branching alternate or proximal rarely opposite.

basal absent at flowering time, internodes between cauline leaves mostly 1.25+ times as long as subtending leaves;

blade elliptic- or oblong-lanceolate, 1.5–7 cm × 4–12(–16) mm.

all cauline at flowering time;

blade linear to narrowly lanceolate, 0.7–3 cm × 1–4.5(–6) mm.

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

pedicels 10–90(–110) mm.

open cymes;

pedicels (2–)10–40 mm.

7–12(–14)-merous;

calyx tube obconic to campanulate, 1.5–4 mm, mid- and commissural veins about equally prominent, 4-ridged;

lobes linear to oblong-lanceolate or occasionally narrowly spatulate or ± foliaceous, 4–20 mm;

corolla purplish pink or rarely white, eye yellow, projections of eye into corolla lobes oblong, sometimes shallowly 3-lobed, usually with a red border, tube (3–)4–8 mm, lobes oblanceolate to narrowly spatulate-obovate, (10–)12–25 × 3–11 mm, apex rounded to subacute;

anthers coiling circinately.

5-merous;

calyx tube campanulate, 2.8–5.5 mm, commissural veins more prominent than midveins, ridged, lobes linear, 9–13 mm;

corolla purplish pink or rarely white, eye yellow or yellowish green, projections of eye into corolla tube oblong to narrowly triangular, alternating with shorter white or paler yellow zones, tube 3–7 mm, lobes narrowly spatulate-obovate, 8–18 × 3–6 mm, apex rounded;

anthers coiling circinately.

 = 34 + 8B.