Bark Mounds, not linked to Guardians. Temp 200-440k
Require <100 lyrs proximity to any nebula ( Galactic core region excluded )
Mostly spawn in numbers of 5 per planet which then increases a few if volcanism is present or decreases down to one or two at the far ends of its temp criteria. ie 300k will have 5 sites + a few more if volcanic. 202k might only have 1 or 2 due to extremes 438k similar results too.
i think folk may be confusing that link with the Brain tree's being linked to Guardian areas , although direct or indirect link and reasons or purpose unknown they are undeniably linked to guardian areas.
Roseous ones were the first set before varieties. Mostly were found in Ejecta's but now appear thats no longer main location criteria on a body now.
Variants now changed that , comes down to system+planetary criteria to determine which variety could be present.
water source needed for the non roseous ones and temp or planet specific requirements too along with geographical location on a planet vary from variety to variety
Those all have criteria and reasons to why they are there or not.
Same goes for NSP but those work on a different set of criteria but those are set by the region to what type of things will be found.
every NSP has a organic or anomaly. and up to two large objects ( crystals, spheres, + some large tree's )
Where the NSP could be is determined by the criteria of the contents of the cloud.
Most NSP will be in systems with high mass codes compared to surrounding systems of that area.
many things will be tied to OBAFGK star sets but not all.
Some do require specific star requirements , common or very rare and that can affect the distribution of NSP in some regions compared to others.