(Inula helenium) This large plant produces stunning yellow sunflower type Van Gogh rays. The mesmerizing yellow flowers of this ornamental medicinal plant proudly stand almost 7 feet tall. The large 2nd year, fall-dug roots have traditionally been used to treat lung ailments and other health issues, though one should always consult a primary care provider for advice on how to use this powerful herb. Even if not used medicinally, it’s a looker in the garden!