First of all, I would like to say thank you for your question.
What’s the difference between an Elfwood and a treant as in J. R. R. Tolkien’s fantasy world Middle-earth?
A treant is a fictional anthropomorphic organism having many characteristics of a tree. Ents are a race of beings in J. R. R. Tolkien’s fantasy world Middle-earth who closely resemble trees. They are similar to the talking trees found in folklore around the world. Their name is derived from the Old English word for giant.
Elfwood is the son of Lugh, or Lughiel, of the Long Arm, the Irish god of kings, justice, and rulership. King of the Fairies. Master of all arts, Lugh served as chief Ollam of the Tuatha Dé Danann; he was also a cunning trickster and the wielder of Assal, the lightning spear. He created Elfwood from an earth tree after the destruction of his world to rejuvenate life on the barren world. Elfwood is a nephilm.
The legend of treant doesn’t refuse to them as being made from the immortal’s essence but moreso from their powers. It is not explained where the Ents come from.
One major difference is an Elfwood can take on a full human appearance and lives as a human as any other demigod or immortal. An ent or treant can not.
The story of the treant and Ent comes from ancient mythology just as the story of Elfwood. A variation existed in every society.
Substantially, they are more alike than not.
They both comes from the same legends.
FestivityLughnasadh or Lughnasa is a Gaelic festival marking the beginning of the harvest season. Historically, it was widely observed throughout Ireland, Scotland and the Isle of Man. In Modern Irish it is called Lúnasa, in Scottish Gaelic: Lùnastal, and in Manx: Luanistyn. WikipediaDate: Sunday, August 1, 2021Celebrations: Offering of First Fruits, feasting, handfasting, fairs, athletic contestsSignificance: Beginning of the harvest seasonObserved by: Historically: Gaels; Today: Irish people, Scottish people, Manx people, Celtic neopagans, WiccansAlso called: Lúnasa (Irish), Lùnastal (Scottish Gaelic), Luanistyn (Manx language)