Scarlet Pimpernel - Anagallis arvensis
Blue-scarlet Pimpernel, Red Pimpernel, Red Chickweed, Poor Man's Barometer, Poor Man's Weather-glass,
Glabrous annual. Stems ascending, prostrate, rooting at basal nodes, 5–40 cm, 4-angled. Leaves opposite, sessile, 9–15 mm long, ovate, rounded at the tip. Inflorescence: flowers solitary from leaf axils; pedicels ascending at first, then recurved, 1–3 cm long. Flowers salmon-colored, rotate; corolla united only at the base, 5–8 mm across, ciliate; sepals linear-lanceolate, 2–4 mm long; filaments hairy. Capsules globose, 3–5 mm across, circumcissile (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Mostly in wet places and often in sandy soil.