Assalamu alaikum wa rehmatullahi wa barakatuh
And the stars and trees prostrate.(55:6)
There is a phenomena known as the axial tilt or obliquity which is the angle formed by a rotating body between its rotational axis and the orbital axis .This inclination or obliquity is exhibited by the planets as well as stars.In short the planets are inclined or tilted.
The same thing is observed in case of stars and is known as Stellar obliquity i.e is the axial tilt of a star with respect to the orbital plane of a planet.
Note the prostration.
This could be the trees really in prostration.
Or the trees responding to gravity in various manners i.e