Not sure of their endangered status but I do know my 2 plants are collected thoughtlessly in the wild. I grow white sage, Salvia apiana, and sweetgrass, Hierochloe odorata.
Here's a story about the sage. A local demonstration garden, run by a Master Gardeners group, has stopped growing white sage because people kept tearing off stems and ruining the plant. They replaced the plant twice and then gave up on it.
White sage is easy enough to grow from seed and the seed is easy to obtain. But I understand that in the wild the plant is harvested by people who sell smudge sticks at art fairs and it has become scarce in the wild on that account.
I believe sweetgrass suffers the same fate.