Those rarefied thorn bush flowers

[Tanok]

Do i have to harvest the thorns to give a chance for flower to spawn or they will spawn eventually if I leave it there long enough? (I know its super rare and I may never see one in my few thorn bushes)
Thanks!

[Soroka]

1)You can snap the spines and get about with a chance of 1 to 400 a flower.
2)You can just find a flower on a bush, there's just a rare chance, for half a year I found a flower from my bush on the plot only once.
3)You can bypass large areas and bring 3 or more flowers at a time at a time.

[Tanok]

Ohh, so you still have the chance on bushes with no flower. Thanks!