Veronica serpyllifolia L.
Family - Plantaginaceae
Stems - Multiple from the base, prostrate to ascending, rooting at the nodes, branching, from fibrous roots, to +30cm long (10-15cm tall), antrorse puberulent, herbaceous.
Leaves - Opposite, very short-petiolate. Petioles to 1mm long, glabrous. Blades orbicular, entire to slightly crenate, green, +/-9mm long, +7mm broad, mostly glabrous or with a few antrorse hairs on margins near the base.
Inflorescence - Terminal bracteate racemes. Bracts narrower and noticeably smaller than leaves. Flower stalks to 2mm long, antrorse puberulent, shorter than the subtending bract.
Flowers - Corolla zygomorphic, whitish-blue with purple stripes internally, glabrous externally, pubescent internally near the apex of the corolla tube, 4-lobed. Corolla tube to .8mm long. Lobes rounded, to 3mm long and broad, entire. Lower lobe reduced. Stamens 2, erect, exserted, alternate and adnate between lateral and central lobes. Filaments to 3mm long, clavate, white, glabrous. Anthers purple, .3mm long. Ovary superior, glandular pubescent, spherical, green, 1.2mm in diameter, 2 locular, many seeded. Placentation axile. Style 2mm long in flower (elongating to 3 mm in fruit), glabrous, translucent to purple near the apex. Stigma capitate. Sepals 4, green, unequal, persistent, mostly glabrous but with some antrorse cilia on margins, to -3mm long, 2mm broad in flower, sub-acute to rounded at apex.
Fruits - 2.8-4.0 mm long, wider than long, heart-shaped in profile, flattened, the notch shallow to moderate (0.3-0.8 mm), the surfaces and margins sparsely glandular-hairy. Persistent style nearly as long as fruit.
Flowering - April - July, sometimes again in the fall.
Habitat - Low wet woods, spring branches, wet slopes, grassy places, waste ground.
Origin - Native to Europe.
Other info. - This little species can be found in the southeastern corner of Missouri. The plant forms mats when left undisturbed. This species is easy to ID because of its growing habit, rounded leaves, and whitish-blue flowers.
Photographs taken in Brown Summit, NC., 10-1-02 (DETenaglia); also near Creve Coeur Lake, St. Louis County, MO, 4-23-2016 (SRTurner).