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.

several, clustered, terete, 5–14 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 lanceolate to ovate-oblong or ovate, 2.5–6(–8.5) cm × 5–30(–45) mm.

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

pedicels 10–90(–110) mm.

corymboid dichasia of compact cymules;

pedicels 1–5 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, 1–2 mm, mid- and commissural veins about equally prominent, not ridged or with low, narrow ridges, lobes triangular to linear-subulate, 0.1–3 mm;

corolla white or cream throughout, tube 2–4 mm, lobes oblong-oblanceolate, 4–7(–9) × 2–3(–4) mm, apex rounded to obtuse;

anthers recurving.

 = 34 + 8B.