Myrrh is the dried sap of several types of trees, but particularly those from Commiphora myrrha and Commiphora gileadensis, native to parts of Middle East and northern Africa including Jordon, Palestine, Ethiopia, Egypt, and lower Saudi Arabia.
Myrrh, as a processed or dried reddish powder or mixed into oil has been used for embalming, anointing or in tombs to mask the odors of decomposition.
Myrrh is often used in chrism for anointing and as an ingredient for incense. It is also used as an herbal remedy for arthritis and as an analgesic for dental and muscle pain.
Biblical references to myrrh:
Take also for yourself the finest of spices: of flowing myrrh five hundred shekels, ... You shall make of these... a holy anointing oil. With it you shall anoint the tent of meeting and the ark of the testimony... You shall anoint Aaron and his sons, and consecrate them, that they may minister as priests to Me. -- Exodus 30:23-33
Therefore God, your God, has anointed you with the oil of gladness beyond your companions; your robes are all fragrant with myrrh and aloes and cassia. -- Psalm 45:7-8
Then, opening their treasures, they offered him gifts, gold and frankincense and myrrh. -- Matthew 2:11
And they brought him to the place called Gol'gotha (which means the place of a skull). And they offered him wine mingled with myrrh; but he did not take it. -- Mark 15:22-23
Nicodemus, who had first come to Him by night, also came, bringing a mixture of myrrh and aloes, about a hundred pounds weight. So they took the body of Jesus and bound it in linen wrappings with the spices, as is the burial custom of the Jews. -- John 19:39-40