Well, this one had me fooled. After I acquired the seed, it took me 5 years to produced beautiful flowering plants, with crazy, fuzzy buds. Then, I discovered it wasn't a native to our area, but to Siberia, the Russian Far East, Mongolia, northeast China, Korea and Hokkaidō, and is sometimes called the Siberian lily.
You will note that the spelling is not quite right for the state of Pennsylvania. The Latin name is misleading due to an error by the botanist John Bellenden Ker, who apparently didn't have his geography nailed down. When he realized his error, he renamed it Lilium dauricum, but the original name is still used (perhaps to fool gullible people like me).
From Wikipedia: Lilium pensylvanicum (dauricum) reaches a height of 30–70 centimetres (12–28 in) and has a width up to 25 cm (10 in). The stem is hard, smooth and straight, the leaves linear to lanceolate, 4–5 cm (1.6–2.0 in) long and 3–4 millimetres (0.12–0.16 in) wide. The plant flowers in June and July with one to six upright, dish-shaped flowers. The flower consists of six tepals curving backward from the center. The seeds mature from August to September. The bulb is roundish with a diameter of about 2 cm (0.79 in).
Lilium pensylvanicum is very undemanding and is easily cultivated. It is sensitive only in relation to drought. Thus the plant is popular in European and American gardens.