Lythrum L. >

Hypanthium narrow-tubular Lythrum
consider the other alternative
Decumbent or ascending, weak, glabrous annual. Leaves mostly alternate, linear to elliptic, 5–10 mm long. Flowers small, solitary, nearly sessile in most of the axils. Floral tube 2–3 mm long, increasing to c. 6 mm in fruit. Petals 1–4 mm long, pale purplish or bluish. Widespread. Wet places. Fl. spring–summer Lythrum hyssopifolia