The olive seldom exceeds thirty feet in height: its leaves are dark green on the upper surface, and of a silvery hue on the under, and generally grow in pairs. Its wood is hard, like that of box, and very close in the grain. It blossoms very profusely, and bears fruit every other year.
The flower is at first yellow, but as it expands, it becomes whiter, leaving a yellow center.
The fruit is first green in color, then pale, and when ripe, black.
It is principally valuable for the oil it produces, which is an important article of commerce in the east. A full-sized tree in full bearing vigor is said to produce a thousand pounds of oil, Jud 9:8,9 2 Chronicles 2:10.
The olive delights in a stony soil, and will thrive even on the sides and tops of rocky hills, where there is scarcely any earth; hence the expression “oil out of the flinty rock,” etc., De 32:13 Job 29:6.
It is an evergreen tree, and very longlived, an emblem of a fresh and enduring piety, Psalm 52:8.
Around an old trunk young plants shoot up from the same root, to adorn the parent stock when living, and succeed it when dead; hence the allusion in describing the family of the just, Psalm 128:3.
It is slow of growth, and no less slow to decay.
The ancient trees now in Gethsemane are believed by many to have sprung from the roots of those, which witnessed the agony of our Lord.
The “wild olive-tree” is smaller than the cultivated, and inferior in all its parts and products. A graft upon it, from a good tree, bore good fruit; while a graft from a “wild” olive upon a good tree, remains “wild” as before. Yet, “contrary to nature,” the sinner engrafted on Christ partakes of His nature and bears good fruit, Romans 11:13-26.
Reference: ATS Bible Dictionary, biblehub.com