From Ovid's "Metamorphoses", Book I:

And as the beagle sees across the stubble
A hare and runs to kill and she for life--
He almost has her; now, yes now, he's sure
She's his; his straining muzzle scrapes her heels;
And she half thinks she's caught and, as he bites,
Snatches away; his teeth touch - but she's gone.
So ran the god and girl, he sped by hope
And she by fear. But he, borne on the wings
Of love, ran faster, gave her nor respite,
Hot on her flying heels and breathing close
Upon her shoulders and her tumbling hair.
Her strength was gone; the travail of her flight
Vanquished her, and her face was deathly pale.
And then she saw the river, swift Peneus,
And called: "Help, father, help! If mystic power
Dwells in your waters, change me and destroy
My baleful beauty that has pleased too well."
Scarce had she made her prayer when through her limbs
A dragging languor spread, her tender bosom
Was wrapped in thin smooth bark, her slender arms
Were changed to branches and her hair to leaves;
Her feet but now so swift were anchored fast
In numb stiff roots, her face and head became
The crown of a green tree; all that remained
Of Daphne was her shining loveliness.

And still Apollo loved her; on the trunk
He placed his hand and felt beneath the bark
Her heart still beating, held in his embrace
Her branches, pressed his kisses on the wood;
Yet from his kisses still the wood recoiled.