It is this image that stands as a contrast to the problem that Tolkien sets up in The Lord of the Rings--the separation of the Ents and the Entwives, who are neither face to face, nor side by side, and this image that we can interrogate using the tale of the Ents, and vice versa.
Additional correspondence addresses potential connections between Bombadil and the Entwives, (4) how Treebeard uses (and modifies) the elvish languages, and the mythological origin of the Ents that Tolkien would later develop in The Silmarillion (Letters 307-8, 334-5).
Most scholarly treatment of the Ents maintains some balance between the Ents as representative of Nature, Tolkien's creative inspiration for the Ents, the Ents' overall function within the power structures of the narrative, and the gendered division of nature that the Ents and Entwives seem to represent.
Uniquely, in Tolkien in the Land of Heroes, Anne Petty situates the Ents and Entwives among the "tales of love and loss" in the legendarium, seeing the story of the Ents and the Entwives as "Tolkien's veiled way of saying that one should not take their [sic] lovers for granted" (210), and Corey Olsen identifies in the Ents' and Entwives' relationship a squandered opportunity for each to complement the efforts of the other as stewards of Middle Earth.
The gendering of differences being crucial to the representation of the marital relationship between the Ents and Entwives, it is necessary to consider the Entwives' gendered identity beyond their gardens and attitude toward nature.
If the Entwives' naming points to the primacy of marriage in the story of the Ent and Entwife, The Silmarillion and Tolkien's intended epilogue to The Lord of the Rings reinforce this emphasis.
The Entwives are more settled; they have progressed to the farming stage.
Entwives, keepers of the garden, along with hobbits and elves, seem to have a sense of place; they are grounded, as are the mature farandolae in Madeleine L'Engle's The Wind in the Door.
The Ents say they have lost the Entwives, but we hear only Treebeard's story.