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 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Mostly in wet places and often in sandy soil.