Mr. David Sellars,
Your post on Saxifraga florulenta made me think of another endangered alpine that was recently delisted. Potentilla robbinsiana is a Pleistocene relic only found in the White Mountains of New Hampshire. The largest population is in a small area with unusual stone. This stone must satisfy some specific nutrient requirement (like calcium) which cannot be obtained from the granite that predominates this mountain range.
This poor little plant was nearly loved to extinction. Picking by botanists and trampling by hikers had reduced its numbers significantly. A rock wall constructed around its habitat, along with signage prohibiting entry, has allowed this little plant to recover. Efforts have also lead to the establishment of populations in new sites. The great success of these efforts allowed for this species to be delisted. It is nice to know that it continues to inhabit its cold windy perch high up in the mountains.