(18/30 of the non-default seed types).
Most of those are stationary or start from the seed plot planted at. One of the biggest benefits of thorns is you take them with you and use them when the opportunity arises without having to use valuable seed plots near the problem (that you might need for something context specific). Only red hot rock seems to accompany you and last (the mace seems to disappear almost immediately, is that a bug?) and poison (but poison is super hard mode). All the rest are used from the location and are often really dangerous (I'm looking at you thwomp).