Flora of North America species comparison

usually single, occasionally 2–several, 4-angled with wings 0.1–0.5 mm wide, 1.5–5(–7.5) dm, branching all opposite or secondary and/or tertiary occasionally alternate.

generally single, 4-angled, sometimes with wings to 0.2 mm wide, 0.6–5 dm, branching all or mostly alternate.

basal and cauline or only cauline present at flowering time;

basal blades spatulate-obovate;

cauline blades linear-oblong to ovate-lanceolate, 0.8–2.5(–6) cm × 3–8(–18) mm.

all cauline at flowering time;

blade lanceolate-elliptic to ovate, that is, widest proximal to or near middle, 0.8–4 cm × 5–20 mm.

cymes of compact cymules;

pedicels 1–2(–4) mm.

open cymes;

pedicels (10–)20–100 mm.

5-merous;

calyx tube widely obconic to campanulate, 1.5–3(–3.5) mm, mid- and commissural veins about equally prominent, low-ridged, lobes linear-subulate or rarely wider, 2–8(–11) mm;

corolla white throughout (sometimes drying yellow or salmon) or occasionally with a yellow eye, projections of eye into corolla lobes, when present, triangular, without a contrasting border, tube 2.5–7 mm, lobes oblanceolate to narrowly spatulate-obovate, 4.5–15 × 1.5–6 mm, apex rounded to obtuse;

anthers coiling circinately.

5-merous;

calyx tube shallowly campanulate, 3–8 mm, commissural veins more prominent than midveins, strongly ridged, distally keeled, lobes linear, (6–)10–22(–32) mm;

corolla pink or occasionally white, eye often absent or not sharply defined, when present greenish yellow, projections of eye into corolla lobes oblong to narrowly triangular with a reddish border alternating with shorter white or paler yellow zones, tube 4–9 mm, lobes obovate, that is, widest distal to middle, 10–25 × (5–)9–15 mm, apex abruptly ± acute;

anthers coiling circinately.

 = 32, 34.

 = 26.