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.

1–several, clustered, proximally terete, distally sometimes ± 4-angled but not winged, 2.5–10.5 dm, branching opposite throughout.

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-lanceolate to narrowly or occasionally widely elliptic-ovate, 1–4(–6) cm × 3–14(–22) mm.

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

pedicels 10–90(–110) mm.

corymboid dichasia of compact cymules;

pedicels 1–8(–15) 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(or 6)-merous;

calyx tube shallowly campanulate, 1–2(–3) mm, midveins somewhat more prominent than commissural veins, low-ridged, commissural veins scarcely ridged, lobes narrowly lanceolate to filiform, (2–)4–9(–14) mm;

corolla white throughout (sometimes drying cream to yellow), tube 2.5–6 mm, lobes oblanceolate, (5–)7–21 × 2.5–8 mm, apex rounded;

anthers recurving.

 = 34 + 8B.

 = 36.