'Every Green Tree' in the Bible

For of old time I have broken thy yoke, and burst thy bands; and thou saidst, I will not transgress; when upon every high hill and under every green tree thou wanderest, playing the harlot.

The LORD said also unto me in the days of Josiah the king, Hast thou seen that which backsliding Israel hath done? she is gone up upon every high mountain and under every green tree, and there hath played the harlot.

Only acknowledge thine iniquity, that thou hast transgressed against the LORD thy God, and hast scattered thy ways to the strangers under every green tree, and ye have not obeyed my voice, saith the LORD.