You might be surprised to learn that the flowers in your photo are not true lilies but rather daylilies or Hemerocallis. They are called daylilies because the flowers usually last no more than one day.
The orange one, Hemerocallis fulva, often called the tawny daylily is a clump-forming perennial, characterized by its beautiful orange flowers which line the roadsides in July. This species is not a true lily, as indicated by its unspotted blossoms and leafless stems. Tawny daylily reproduces primarily by rhizomes (horizontal underground stems) and tuber-like roots, and rarely by seeds. It spreads rapidly and can be considered invasive.
Tawny daylily may be confused superficially with the native wood lily (Lilium philadelphicum), a true lily whose orange, upright flowers may be seen blooming along roadsides and in clearings. However, the wood lily has spotted flowers and leaves growing along the length of the stem.
The yellow daylily (also called lemon lily, Hemerocallis lilioasphodelus) is another introduced species from Asia that has spread from cultivation. It can be distinguished from tawny daylily by its fragrant, yellow, spring- to summer-blooming flowers, and its smaller stature.
Many new daylily hybrids have been or are being developed, providing a wide variety of flower colors, shapes and sizes, as well as flowers that may last a week or more.
For more information on the tawny daylily,see the link below: