Yellow Loosestrife

Yellow loosestrife is a tall perennial of the primrose family, growing two to four feet high on shady banks and by streams. Grieve describes a creeping root, slightly branched downy stems, nearly stalkless leaves in pairs or whorls of three or four, marked with dark glandular dots, and golden five-petalled flowers in July and August. She stresses that it is unrelated to purple loosestrife, and only called a willow herb by a superficial likeness. Wikipedia describes it as flowering from June through August in the British Isles, with orange-margined sepals and leaves spotted with translucent orange glands. Grieve records its use as an astringent for bleeding and diarrhoea.