Rhizomatous perennial, glabrous throughout, with erect or ascending simple stems 1-10 dm; lvs opposite, all short-petiolate, serrate to subentire, lanceolate or lance-ovate to narrowly subtriangular, or the lower more elliptic, 1.5-8 נ0.6-3 cm, generally 2-4 times as long as wide; racemes axillary, pedunculate, open, mostly 10-15-fld; cor 5-10 mm wide, blue; style 2.5-3.5 mm; mature pedicels divaricate, 5-15 mm; fr turgid, 3 mm long and about as wide, scarcely notched; seeds numerous, 0.5 mm or less; 2n=36. Swamps and streambanks; Nf. to Alas., s. to N.C., Mo. and Calif.; also ne. Asia. May-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Duration: Perennial Lifeform: Forb/Herb General: Perennial, aquatic to emersed, 5-35 cm tall; stems erect to ascending, usually decumbent at the base and rooting at the lower nodes, usually branched; herbage glabrous; rhizomatous. Leaves: Cauline, opposite, lanceolate to ovate, 0.5-5 cm long, 0.3-3 cm wide, glabrous, margins crenate-serrate, or sometimes nearly entire towards the base, base wedge- shaped, rounded, to sub-cordate, apex acute to obtuse; petiole short. Flowers: Inflorescence a spike-like panicle, compact, dense, yellowish woolly tomentose; pedicels very short; calyx segments 5, lanceolate, 8-12 mm long; corolla disc- shaped, 1.2-3 cm in diameter, yellow, seldom white, lobes 5, usually stellate-pubescent on back; stamens 5; flowers April-September. Fruits: Capsule, both septicidal and loculicidal, orbicular, 2.5- 3.8 mm long, 3-4 mm wide, often slightly notched at the apex; seeds numerous, brownish. Ecology: Springs, slow-flowing streams, lake margins, meadows, often rooted in saturated soils; 600-2900 m (2000-9500 ft); Apache, Cochise, Coconino, Gila, Graham, Greenlee, Maricopa, Mohave, Navajo, Pinal, and Yavapai counties; widely distributed throughout North Notes: Veronica anagallis-aquatica (water speedwell), an introduced perennial, is similar to V. americana but is distinguished by the leaves being sessile and somewhat clasping (sometimes the lower blades short-petiolate); racemes are more than 30-flowered; and the corolla is blue or pale violet with purplish guidelines. It occurs in similar habitats. Veronica americana is a host plant for the common buckeye butterfly. It is used by the Navajo as a ceremonial emetic. Editor: Springer et al. 2008