“Onycha” is one of the most mysterious substances mentioned in the Bible. It occurs as an ingredient in the recipe for sacred incense given in Exodus 30 v.34:"

The Onycha is a rockrose
Hebrew: shecheleth
The onycha referred to in Exodus is a rockrose that produces a gum known as labdanum. Onycha blossoms are fully three inches across, white and have at the base of every petal a lot blotch of scarlet-rose deepening to black. Its golden center is made up of a hundred small stamens and a pistil. Onycha in Greek means "fingernail." This probably comes from markings on the petals. The three feet tall bush is a mass of blossoms all through the dry season. Leaves are dark sage green, strongly scented and finely veined. Late in the year a soft glutinous resin exudes from the leaves and stems. This resin is very fragrant and aromatic. Orientals credit it with great medicinal properties and it was highly regarded in biblical times. According to Dioscorides the resin of this plant was first noted long ago because of a herd of goats; the animals, after roaming among the young onycha shoots would return home with their long beards coated with a sticky substance that hardened in the air.
Exodus 30:34 (KJV) And the LORD said unto Moses, Take unto thee sweet spices, stacte, and onycha, and galbanum; these sweet spices with pure frankincense: of each shall there be a like weight:
Exodus 30:35 (KJV) And thou shalt make it a perfume, a confection after the art of the apothecary, tempered together, pure and holy:
Exodus 30:36 (KJV) And thou shalt beat some of it very small, and put of it before the testimony in the tabernacle of the congregation, where I will meet with thee: it shall be unto you most holy.

Rock Rose (Cistus creticus) : Folk names are European rock rose, labdanum, onycha, and frostwort. The gum resin is used. Use for success and prosperity. The oil smells like ambergris. The gum resin is a natural exudation, and burns with a clear flame. This is associated with the Sun.

page 376 Onycha : see Rock Rose