The Myth -------
the myth of Daphne & Apollo can be found in Ovid's Metamorphoses book one. Here is a summary of the myth:

Daphne was a nymph (naiad, nymph of freshwater streams) in Artemis's group who, along with all the other nymphs, made a vow of chastity. Her father was Peneus, a river god.
Apollo was the god of light, music, youthfulness, science, healing, and music. He was commonly seen with a lyre and skilled in the bow and arrow, much like his twin sister Artemis. Their parents were Zeus and Leta (a mortal woman).

Daphne was Apollo's first love, but it was caused by Eros's (Cupid's) arrrow. Apollo had insulted Eros, saying that he was better at the bow than he. So Eros sent two arrows, one with a blunt end tipped in lead that made people reject the first person they saw. The other arrow, a sharp one tipped in gold, made that person fall in love. With the lead arrow, he hit Daphne, and with the golden arrow, he hit Apollo. Now Apollo is aflame with love for Daphne and thus he pursues her. However, Daphne is disgusted by even his name, for she only wants to run free with the animals and has no need for marriage.

Apollo runs after Daphne, telling her to come back, and fears that she will fall and harm her faultless body. He says that he is a worthy lover since he is Zeus's son and says there is no herb that can cure his passion, even though he is god of medicine. But she flees and he keeps chasing her, and he is faster. She can feel his breath and knows he is getting closer so she prays to her father, a river-god, to tranform her shape into something less desirable. As she speaks, she is transformed into a laurel tree. However, Apollo still loves her, and clasps the tree as if it were her. Therefore, he names the laurel tree his and is now always seen with a crown of laurel leaves around his head, lyre, and quiver. All the Roman generals from henceforth wear laurel garlands when they celebrate victory. As Apollo declared this, the laurel nodded as if it agreed.

Excerpt from the myth:
"So ran the god and girl, one swift in hope,
The other in terror, but he ran more swiftly,
Born on the wings of love, gave her no rest,
Shadowed her shoulder, breathed on her streaming hair.

"Her strength was gone, worn out by the long effort
Of the long flight; she was deathly pale, and seeing
The river of her father, cried 'O help me, dear father,
If there is any power in the rivers,
Change and destroy the body which has given
Too much delight!' And hardly had she finished,
When her limbs grew numb and heavy, her soft breasts
Were closed with delicate bark, her hair was leaves,
Her arms were branches, and her speedy feet
Rooted and held, and her head became a tree top,
Everything gone except her grace, her shining.

"Apollo loved her still. He placed his hand
Where he had hoped and felt the heart still beating
Under the bark; and he embraced the branches
As if they still were limbs, and kissed the wood,
And the wood shrank from his kisses, and the god
Exclaimed: 'Since you can never be my bride,
My tree at least you shall be! Let the laurel
Adorn, henceforth, my hair, my lyre, my quiver:
Let Roman victors, in the long procession,
Wear laurel wreaths for tryumph and ovation.
Beside Augustus' portals let the laurel
Guard and watch over the oak, and as my head
Is always youthful, let the laurels always
Be green and shining!' He said no more. The laurel,
Stirring, seemed to consent, to be saying Yes."
---from Ovid, Metamorphoses