Veronica anagallis-aquatica
Sp. Pl. 1: 12. 1753.
Annuals or perennials. Stems erect or prostrate basally, (20–) 30–100 (–170) cm, usually thick-fleshy, glabrous. Leaves: petiole 0–2 (–8) mm (basal lateral branches usually distinctly petiolate to 8 mm) proximally, 0 mm distally; blade (of proximal leaves) ovate, elliptic, or oblong, (15–) 30–80 (–145) × (7–) 10–30 (–45) mm, 1.5–3 times as long as wide, base obtuse proximally to cordate-amplexicaul in middle and ± cuneate distally, margins ± serrulate or denticulate, apex acute, surfaces glabrous, rarely glandular-hairy. Racemes 6–25, axillary, 50–100 (–150) mm, 5–10 mm diam., (20–) 30–40 (–60) -flowered, axis glabrous, rarely glandular-hairy; bracts linear to lanceolate, 2–5 mm, apex acute. Pedicels suberect or arcuate-erect to subpatent, curved upwards in fruit, 3–7 (–10) mm, longer than subtending bracts, glabrous or hairy. Flowers: calyx lobes 2–3 mm, apex acute, glabrous, rarely hairy; corolla lavender to pale blue, rarely pale lilac, (4–) 6–8 mm diam.; stamens 3–3.5 mm; style 1.5–2.5 mm. Capsules slightly compressed in cross-section, globular, (2.5–) 3–3.5 (–4) × 2.5–3.2 (–4) mm, apex rounded or ± emarginate, glabrous or sparsely short-glandular-hairy. Seeds 40–77, yellowbrown, ellipsoid to subglobular, planoconvex, (0.3–) 0.5–0.7 × 0.3–0.5 mm, 0.2–0.3 mm thick, smooth. 2n = 36.
Phenology: Flowering Mar–Sep(–Nov).
Habitat: Stream margins, ditches, banks, springs, swamps, wet meadows.
Elevation: 0–4000 m.
Distribution
Introduced; Alta., B.C., Ont., Ariz., Calif., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Mich., Mo., Mont., Nebr., Nev., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.Dak., Tenn., Tex., Utah, Va., Wash., W.Va., Wis., Wyo., Eurasia, Africa, Atlantic Islands, likely also in Mexico, Central America, South America
Discussion
Veronica anagallis-aquatica is widespread. It is not clear whether it is native to the flora area; it is certainly introduced in some states and commonly dispersed by human activity. The species varies with water availability. It is frequently confused with V. catenata. Ecological differences (see discussion under 15. V. catenata) may suggest that V. anagallis-aquatica does not occur in most parts of Canada and Alaska from which the species is reported but is present in some states excluded from the distribution area due to the lack of herbarium specimens seen (for example, Alabama, Arkansas, Idaho, Louisiana, Maryland, Massachusetts, Mississippi, South Carolina, and Vermont). Hybrids are frequent in Europe (V. ×lackschewitzkii J. Keller) and have been reported for California and Nebraska (L. R. Heckard and P. Rubtzoff 1977). The sterile hybrids never form capsules and bear relatively long inflorescences. Another closely related species, V. anagalloides Gussone (= V. salina Schur), is not present in North America.
Selected References
None.