Laudator Temporis Acti

Greek Anthology 9.706 (Antipater, tr. W.R. Paton):

I am a holy tree. Beware of injuring me as thou passest by, stranger, for I suffer pain if I am mutilated. Remember that my bark is still virginal, not like that of savage wild pear-trees. Who does not know what the race of poplars is like? If thou dost bark me, as I stand here by the road, thou shalt weep for it. Though I am but wood, the Sun cares for me.

Δένδρεον ἱερόν εἰμι· παρερχόμενός με φυλάσσευ
  πημαίνειν· ἀλγῶ, ξεῖνε, κολουομένη.
μέμνεο, παρθένιός μοι ἔπι φλόος, οὐχ ἃπερ ὠμαῖς
  ἀχράσιν· αἰγείρων τίς γένος οὐκ ἐδάη;
εἰ δὲ περιδρύψῃς με παρατραπίην περ ἐοῦσαν.
  δακρύσεις· μέλομαι καὶ ξύλον Ἠελίῳ.

A.S.F. Gow and D.L. Page on line 3:

When Phaethon in the chariot of the Sun, his father, was struck by lightning and fell into the Eridanus, his sisters, the Heliades or Phaethonti(a)des, weeping on its banks, were turned into poplar-trees.^1
1 Alders in Virg. Ecl. 6.63 (but poplars in Aen. 10.190).

Ovid (Metamorphoses 2.340-365, tr. Brookes More) tells the story of the transformation of the Heliades into poplars:

And all the daughters of the Sun went there
giving their tears, alas a useless gift;—
they wept and beat their breasts, and day and night
called, "Phaethon," who heard not any sound
of their complaint:—and there they lay foredone,
all scattered round the tomb. The silent moon
had four times joined her horns and filled her disk,
while they, according to an ancient rite,
made lamentation. Prone upon the ground,
the eldest, Phaethusa, would arise
from there, but found her feet were growing stiff;
and uttered moan. Lampetia wished to aid
her sister but was hindered by new roots;
a third when she would tear her hair, plucked forth
but leaves: another wailed to find her legs
were fastened in a tree; another moaned
to find her arms to branches had been changed.
And while they wondered, bark enclosed their thighs,
and covered their smooth bellies, and their breasts,
and shoulders and their hands, but left untouched
their lips that called upon their mother's name.
What can she do for them? Hither she runs
and thither runs, wherever frenzy leads.
She kisses them, alas, while yet she may!
But not content with this, she tried to hale
their bodies from the trees; and she would tear
the tender branches with her hands, but lo!
The blood oozed out as from a bleeding wound;
and as she wounded them they shrieked aloud,
"Spare me! O mother spare me; in the tree
my flesh is torn! farewell! farewell! farewell!"
And as they spoke the bark enclosed their lips.
Their tears flow forth, and from the new-formed boughs
amber distils and slowly hardens in the sun.

Related posts: Cactus Ed and Arboricide; Views from the Center of Highgate Wood; Artaxerxes and Arboricide; When the Last Tree Falls; The Hamadryads of George Lane; Sorbs and Medlars; So Foul a Deed; Like Another Erysichthon; The Fate of Old Trees; Scandalous Misuse of the Globe; The Groves Are Down; Massacre; Executioners; Anagyrasian Spirit; Butchers of Our Poor Trees; Cruel Axes; Odi et Amo; Kentucky Chainsaw Massacre; Hornbeams; Protection of Sacred Groves; Lex Luci Spoletina; Turullius and the Grove of Asclepius; Caesarian Section; Death of a Noble Pine; Two Yew Trees in Chilthorne, Somerset; The Fate of the Shrubbery at Weston; Willows; The Trees Are Down; Sad Ravages in the Woods; An Old Saying; Strokes of Havoc; Maltreatment of Trees; Arboricide; An Impious Lumberjack; Erysichthon in Ovid; Erysichthon in Callimachus; Vandalism.