Ok, let's get started! Alexander the Great: did you know he was hero of a romantic epic popular across the medieval world? Between the 4th-16th cent., it was translated from Greek to Coptic, Ge'ez, Byzantine, Arabic, Persian, Armenian, Syriac, Hebrew & most European vernaculars
An international bestseller! Supposedly an account of Alexander's exploits, it is full of bits of lore, fantastical tales, & myth picked up from the various cultures it filtered through. One of these is the trope of the Waqwaq/talking tree (Image: Chester Beatty, Per 104, f. 48) 
This story comes from one of Alexander's letters to his tutor Aristotle about his trip to India (translated here: attalus.org/translate/alex…). When he arrives, the first thing he does, as is his habit, is to ask the wise men he meets to show him their most wondrous sites.
The Indians know exactly what he'll want to see: "King, we have a marvel to show you worthy of your attention. For we will show you inanimate objects which talk like men." Image: Iskandarnama (Biblioteca nazionale marciana Or. 90, f. 177a)
Also as is his habit, Alexander reacts with violence: he has the men beaten for lying to him. But he's curious and decides to go see this supposed marvel for himself. Image: Alexander beating a drum, Khamsa of Nizami (British Library Or. 6810, f. 227v)
He goes on a 15-day journey, to the furthest border of this civilization, and is led to the "trees of the sun and moon." The tree of the sun speaks 3 times a day, while the tree of the moon does the same at night (British Library Royal 15 E VI fol. 18v)
Alexander tries to go in with his army, but the natives tell him that no iron is allowed. Though he gives up his weapons, he fears treachery and tells his men to surround the grove. Then he goes inside with a local guide. Shahnama (Universitesi Kutuphanesi F. 1406, f. 114b)
When the sun rises, a voice in the native language comes from the tree. The guides become nervous, not wanting to translate for this impetuous foreign king. But when he insists, they tell him the tree said he will soon die at the hands of his friends (Image: BM Or. 2834, f. 356r)
Alexander decides he wants a second opinion. He goes back on his own at dusk to see what the tree of the moon says. It speaks in his language, saying he won't make it home to his mother but will die in Babylon. Image: Ibrahim Sultan's Shahnama, Bodleian, Ouseley Add. 176, f. 311b
Alexander spends a sleepless night worrying, then goes back one more time at sunrise with a small entourage, asking, "If the years of my life have been fulfilled, I wish to learn from you this: can I return to Macedonia and comfort my mother and my wife, and then return?"
The tree says that he will not go home before dying. Some versions, like the Armenian, say why: "The reason? You deprived many men of the sight of their mothers and cities and countries and friends. And just as one sows, so in fact shall he reap." Rylands Armenian MS 20, f. 255
It goes on to describe the horrific deaths of his mother, his wife, and his brothers to follow his own, and Alexander leaves the place as soon as he is able. Image: Rylands Armenian MS 20, f. 227
Well, that ended up being longer than I thought! But there are a few things you may have noticed: first, that many of these paintings are from Persian manuscripts of the Shahnama, or the Khamsa of Nizami, not "The Alexander Romance", as the Armenian ones are.
Second, you may notice that many of the paintings show heads in the trees, whether human or animal, male or female, while the story itself never refers to speaking heads but rather to the trees themselves speaking.
The simple answer to the first question is that tales of Alexander/Iskandar ended up in the Shahnama, the Khamsa, and other tales of history in the Persian tradition. These stories were more respected, and as such more likely to be illustrated, than popular tales like the Romance
The answer to the second question is more complicated. At first I thought that perhaps the Persian versions of the story mentioned heads, but in fact they decidedly do not: they say that the voices came from "wailing leaves" of the trees.
A 1935 article by Phyllis Ackerman posited that this trope is "a lingering memory of the ancient Fertility Goddess cult, with the associated animal attributes, tree-worship and sun deification" based on ancient Indian seals depicting trees associated w/ animal heads and goddesses
Partially some of the motifs could have persisted over time. These painters also, however, would have heard of the Waq-waq tree from Arabic travel writers, which sprouted human heads. It's also possible that they were representing the animal skins adorning the trees.
We don't know for sure, but the motif really took off in Persian art, which I can talk more about next week! If you made it this far in my massive thread, thanks so much, and happy weekend-- I hope you enjoyed!
