Another one is bowing.
Were the Earth much further from the Sun and below Mars, the lost planet Saturn, and presumed Jupiter above Saturn, the orbital mechanics would lead to a slight asymmetry in the straight line configuration. They would curve slightly in their outer orbit of the Sun. So looking north while Saturn would dominate the sky, the crescent of Jupiter would be visible on the side facing the Sun.
With Earth rotating in line with Saturn, the crescent of Jupiter would be high in the sky during the day, and low at night. The daily rotation would be the same as today though.
Being so far from the Sun then, the sunlight would give light but little heat or ultraviolet, just because of the distance.
The source of ultra-violet would be the crescent. Surely what is referred to as the Grail in English legends.
All plants would point north, towards God. They would "bow" - literally lean northwards towards the source of ultraviolet.
If that asymmetry was lost the grail would disappear, and without it the plants would start to die. They may be heat, reduced, from Saturn, but the bowing towards "God" would stop and they would wither. This is surely the Wasteland referred to with Percival and likely the same famine as in the Biblical story of Joseph.
Once the asymmetry was restored and crescent to, the plants would be restored to life and "bow" again to the Lord.
That will be the origin of bowing. Honouring ones Lord and Master as even the plants and trees did, in imitation.
In later times with the Earth nearer the Sun and enough heat and ultra-violet from the Sun, the plants would no longer "bow". But people still do. The role of King is after all a direct continuation of the King of the Sky and it would make sense to imitate and then continue this custom even to the present day.
There should be evidence of a northern lean for plants in antiquity. But I think it likely that is the origin of bowing. It is what you see on Egyptian bas-reliefs, of people bowing towards the "Re", the rays of the Sun.