Sp. Pl. 1: 14. 1753.
Annuals. Stems erect or ascending, (2.5–)4–25(–35) cm, glabrous or densely glandular-hairy. Leaves: blade oblanceolate proximally, narrowly oblong distally, 5–28(–35) × 2–6(–10) mm, 3–10 times as long as wide, base cuneate, margins entire or dentate distally, apex acute, surfaces glabrous or densely glandular-hairy. Racemes 1, terminal, sometimes 1 or 2 axillary, 20–200 mm, (2–)5–40-flowered, axis glabrous or densely glandular-hairy; bracts spatulate to linear-lanceolate, 3–22 mm. Pedicels erect, 0.2–1(–2) mm, much shorter than subtending bract, glabrous or densely glandular-hairy. Flowers: calyx lobes (2–)3–6 mm, 0.9–2 mm wide, apex obtuse to acute, glabrous or densely glandular-hairy; corolla white or pale pink, 2–5 mm diam.; stamens 1 mm; style 0.1–0.5 mm. Capsules strongly compressed in cross section, obcordiform, 2.5–5 × 2.5–6 mm, apex ± emarginate, glabrous. Seeds 12–140, yellow or pale brown, oblong, flat, 0.6–1.6 × 0.4–0.9 mm, 0.1–0.2 mm thick, smooth. 2n = 52.
Phenology: Flowering (Feb–)Mar–Jun(–Nov).
Habitat: Moist waste lands, gardens, roadsides, stream banks, pond shorelines, vernal pools, other cultivated land.
Elevation: 0–700(–3000) m.
Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Mexico (Baja California, Baja California Sur, Chihuahua, México, Sonora), Central America, South America, Eurasia, Australia.
Stem indument of Veronica peregrina has been used to distinguish var. xalapensis with a glandular-hairy stem (F. W. Pennell 1935), a variety that seems to be confined to drier places than the type variety. Variety laurentiana is also differentiated from var. peregrina in having a glandular-hairy stem, fleshier leaves, shorter stamens, smaller corollas, and slightly differently shaped capsules (Frère Marie-Victorin and J. Rousseau 1940).