Elder berry and flower are great; but remember to leave the bark alone.
Oh Elder! As their name suggests, Elder is a plant that has been gifting us their wisdom and medicine for a long time. And one with an ironic sense of humor. Elder's flowers and berries are exceptionally magic for boosting our immune system and regulating heat; but get too greedy and mess with the bark and it will not be a pleasant encounter. Ah, well- balance in all things I guess.
Elder has a long track record of immune boosting goodness; and is tasty to boot.
While wise, Elder isn't the "stoic oracle" we sometimes project onto the characteristic of wisdom. It's moving, protective and energizing with a grounded vigor - as opposed to the "ZING," "ZAP," "POW" that we've been programmed to feel as energizing. If your system tends to run cold, be moderate with Elderflower. They may cool you down further.
Elder's berry (the dark purple variety!) has become quite popular given its' immune boosting properties, along with being tasty in honey syrups. Filled with rich vitamins and antioxidants it is a general overall booster; it also has components that are known anti-inflammatories. A little tea of steeped berries has been known to get your bowels moving again. Not necessarily a "tonic" herb, I reach for elderberry in specific imbalance situations, particularly during cold and flu season, rather than just for general overall health.
Elder's flower is actually one of my faves. (shhhhh-don't tell the others) Super useful in moving and gently releasing heat in the body, elderflower has historically been used to assist with fever reduction. It is also helpful for any imbalances that include inflammation of the respiratory tract. Some people have met elderflower before: it is the infusion of elderflower that gives the liqueur St. Germain its' distinctive flavor.
Reminder: as I introduce these plants here, it is more of a cursory introduction. Always do a little deeper research on your own to determine if they're a good match for your system. Either in connection with an herbal practitioner or through reputable resources. (The Google is amazing, but...) If you need some pointers on where to go, I've posted additional resources that I've found particularly helpful.