What was the crown of thorn in the Lord's Passion made of?
The Church does not have a definitive answer to this question, but it leans towards a plant called the Christ's thorn jujube (Zizyphus spina-christi).
Ziziphus spina-christi, known as the Christ's thorn jujube, is an evergreen tree or plant native to northern and tropical Africa, Southern and Western Asia. It is native to the regions Levant, East Africa and some tropical countries.
In the Levant, a hundred years ago, it was called sidr (associated with the Lote-trees of the Quran) and was common in the Jordan Valley and around Jerusalem. There were some folklore traditions that said the trees were protected by benevolent spirits or dead saints (weli). By some traditions, it was the tree from which Jesus' crown of thorns was made.2 Easton argues that the spina-christi is too brittle to be bent into a crown, and suggests another local plant which he says is called "nabk."
The oldest known Ziziphus is located south of Jerusalem, in Ayn Husb, Palestine. It estimated to be about 2000 years old. It is believed locally to be the very tree from which Jesus' crown of thorns was made.
The Catholic Encyclopedia basically states that it was also the Zizyphus spina-Christi plant, more popularly known as the, the jujube-tree.
Image from The Passion of the Christ.
Blessed Anne Catherine Emmerich, the 19th-century German nun and mystic whose visions of the Passion inspired Mel Gibson’s movie, The Passion of the Christ, described the crowning of thorns as follows:
In the middle of the court there stood the fragment of a pillar, and on it was placed a very low stool which these cruel men maliciously covered with sharp flints and bits of broken potsherds. Then they tore off the garments of Jesus, thereby reopening all his wounds; threw over his shoulders an old scarlet mantle which barely reached his knees; dragged him to the seat prepared, and pushed him roughly down upon it, having first placed the crown of thorns upon his head. The crown of thorns was made of three branches plaited together, the greatest part of the thorns being purposely turned inwards so as to pierce our Lord’s head. Having first placed these twisted branches on his forehead, they tied them tightly together at the back of his head, and no sooner was this accomplished to their satisfaction than they put a large reed into his hand, doing all with derisive gravity as if they were really crowning him king. They then seized the reed, and struck his head so violently that his eyes were filled with blood; they knelt before him, derided him, spat in his face, and buffeted him, saying at the same time, ‘Hail, King of the Jews!’ Then they threw down his stool, pulled him up again from the ground on which he had fallen, and reseated him with the greatest possible brutality.
Emmerich, Anna Catherine (2011-03-30). The Dolorous Passion of Our Lord Jesus Christ (Kindle Locations 2934-2942). . Kindle Edition.
Sainte-Chapelle, if you are unfamiliar with it, is not simply a little museum for relics of the French royal households. It is a “chapel” (though one could be excused for considering it a cathedral) and is considered one of the great masterworks of Gothic architecture in all of Europe. That Sainte-Chapelle was built primarily to house this relic gives some sense of its great historical importance to the faithful.
While it is impossible to know if this is the actual crown of thorns, it has been venerated as such for many hundreds of years. It is one of the treasures of Christendom, and only makes rare public appearances. - Is This Relic Really Christ’s Crown of Thorns?
Relic of the Crown of Thorns, bought by Louis IX from Baldwin II. It is preserved today in Notre Dame de Paris.