Flora of North America species comparison

10–40 mm.

100–350 mm, freely branched.

60–160 × 3–5 mm;

blade linear, margins entire, veins conspicuous or not, abaxial surface villous, adaxial glabrous, rarely sparsely villous.

cauline, opposite, 60–80 × 1–3 mm;

blade linear to linear-lanceolate, margins entire or toothed, veins conspicuous or not, surfaces hairy.

800–1600 mm, hairy, hairs antrorse, long and short.

100–650 mm, hairy.

greenish or brownish, (20–)150–250 mm, densely flowered, flowers in whorls or pairs;

bracts ovate or triangular, 1–3.5 mm, length 0.4–0.8 times sepals.

greenish or brownish, (50–)150–250 mm, densely flowered, eglandular;

bracts proximal strongly differing from distal, ovate, 2–5(–7) mm, length 1–1.5 times sepals, proximal bracts: apex acute.

sepals 3–4 mm;

corolla bilaterally symmetric, lobes reflexed, adaxials 2.4–3 mm, laterals asymmetric, base cordate;

stamens 4, connective elongated, apex acute.

sepals 2–3 mm;

corolla radially symmetric, lobes reflexed, 2–4 mm, base obtuse;

stamens 4.

2, 2.8–3.2 mm.

2, 2–2.5 mm.

= 20.

= 12.