Sp. Pl. 1: 12. 1753.
Perennials. Stems creeping to ascending, 5–40 cm, scattered eglandular hairs only, often also with glandular hairs, sometimes glabrate. Leaves: blade oblong-lanceolate to ovate, 8–25 × 5–13 mm, 1.5–2.5 times as long as wide, base cuneate, margins subentire or serrulate-crenate, apex rounded to short-acuminate, surfaces glabrate. Racemes 1, terminal, 50–100 mm, 10–30(–60)-flowered, axis eglandular- and glandular-hairy; bracts oblong, 4–7 mm. Pedicels erect, 2–5 mm, 4–6 mm in fruit, shorter than subtending bract in flower, eglandular- and, sometimes, glandular-hairy. Flowers: calyx lobes 2–3 mm, apex acute, ciliate; corolla white, blue, or pink, with purple or dark blue veins (except on abaxial lobe), rotate, 5–8 mm diam.; stamens 2.5–3 mm; style 2–4 mm. Capsules compressed in cross section, obcordiform, 2.5–3.5 × 4–5.5 mm, wider than long, apex acutely emarginate, glandular-ciliate, otherwise glabrate. Seeds 50–72, brown, ellipsoid, flat, 0.6–1.1 × 0.4–1 mm, 0.2 mm thick, smooth. 2n = 14.
Phenology: Flowering Apr–Aug.
Habitat: River banks, wet places, moist meadows, shady forests.
Elevation: 0–3300 m.
Alta., B.C., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask., Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Mexico (Baja California), South America, Eurasia, Australia.
Alpine plants of Veronica serpyllifolia with bright blue, larger corollas, and smaller, hairier raceme axes have been treated at various ranks under the epithet humifusa. The characters are labile and show intergradations with the typical plants. Veronica serpyllifolia is widespread; it is not clear where it is native.