The Woman who Became a Walnut Tree
translation based on the interlinear of Oliver LaMère
Hočąk-English Interlinear Text
Once men had a town there. Then in the fall when the walnuts ripened, one woman ate a walnut and she liked it so much that when she was done she would not sell any of them. They went to the village there, but she would not come. And as she kept herself there her legs transformed into tree roots. When they tried to cut them away, they failed, and soon she became a great walnut tree. It is said that the woman became a tree.
The End 
Commentary. This appears to be a morality tale in which a woman becomes so inordinately fond of walnuts that she fails to share them even for a price. Thus her punishment for being obsessed in this way was to become the object of her obsession.
However, on closer examination we see that the punishment strangely fits the crime. The walnut tree hoards its fruits only up to the point at which it becomes ripe; then it is either harvested or falls to the ground. Thus the walnut tree never gets to keep the ripe and tasty nuts. So the woman who horded the nuts for their rich, ripe taste, now is a being that cannot retain the very thing that she most desires. She is now forced to give away the crop entirely with nothing left for herself — the exact opposite of her human behavior.
Comparative Material. The Hočąk waiką is similar to the Greek story of Tantalus who stole the divine food, the ambrosia, and shared it among his mortal friends. His punishment was never to be able to sate his appetite. He hung from a tree like one of its fruit, and all about him hung a myriad of other kinds of fruit, none of which he could ever grasp, although they were always within his reach. Below him was a pool of water which would sometimes well up within reach, but whenever he scooped the water into his hand, it would all drain away before he could bring it to his lips.  His punishment for giving into his appetite to take the best food of all is to suffer the fate of not being able to taste any food whatever.
In the tale of Philemon and Bacis the poet describes a transformation of man to oak similar to our waiką:
Old Baucis look'd where old Philemon stood,
And saw his lengthen'd arms a sprouting wood:
New roots their fasten'd feet begin to bind,
Their bodies stiffen in a rising rind:
Then, ere the bark above their shoulders grew,
They give, and take at once their last adieu.
At once, Farewell, o faithful spouse, they said;
At once th' incroaching rinds their closing lips invade. 
Greek mythology has many arboreal metamorphoses, and the parallels could be multiplied many fold.
Links: Tree Spirits, Wood Spirits.
Stories: mentioning trees or Tree Spirits: The Creation of the World, The Twins Retrieve Red Star's Head, The Children of the Sun, Visit of the Wood Spirit, The Boy who would be Immortal, The Commandments of Earthmaker, The Old Woman and the Maple Tree Spirit, The Oak Tree and the Man Who was Blessed by the Heroka, The Pointing Man, The Abduction and Rescue of Trickster, The Baldness of the Buzzard, Trickster Eats the Laxative Bulb, Trickster Loses His Meal, The Journey to Spiritland (v. 2), Thunderbird Clan Origin Myth, Waruǧápara, The Chief of the Heroka, The Red Man, The Shell Anklets Origin Myth, The Annihilation of the Hočągara I, Baldheaded Warclub Origin Myth, The Blessing of the Bow, Pete Dupeé and the Ghosts, The Spirit of Gambling, Peace of Mind Regained, The Necessity for Death.
Themes: a person's body turns into a plant: Fourth Universe (white flower), White Flower (white flower), The Boy who would be Immortal (tree), Aračgéga's Blessings (inverse: log > human), cf. The Wild Rose, Deer Clan Origin Myth (v. 2). a person obsessively craves for himself what a tree possesses, and as a consequence is transformed into a tree: The Boy who would be Immortal.
 "Tale of the Woman who became a Walnut, " in Paul Radin, Winnebago Notebooks, Winnebago III, #11a, Freeman #3892 (Philadelphia: American Philosophical Society) pp. 70-72 (140a -140 b).
 Diodorus Siculus 4.74; Plato, Cratylus 28; Lucian, Dialogues of the Dead 17; Homer, Odyssey 11.582-592; Ovid, Metamorphoses 4.456; Pindar, Olympian Odes 1.60; Apollodorus, Epitome 2.1; Hyginus, Fabulæ 82.
 Ovid, Metamorphoses 8.714-720.