“Although the ripe, cooked berries (pulp and skin) of most species of Sambucus are edible, uncooked berries and other parts of plants from this genus are poisonous. Leaves, twigs, branches, seeds, roots, flowers, and berries of Sambucus plants produce cyanogenic glycosides, which have toxic properties. Ingesting a sufficient quantity of cyanogenic glycosides from berry juice, flower tea, or beverages made from fresh leaves, branches, and fruit has been shown to cause illness, including nausea, vomiting, abdominal cramps, diarrhea, and weakness. In August 1983, a group of twenty-five people in Monterey County, California became suddenly ill by ingesting elderberry juice pressed from fresh, uncooked Sambucus mexicana berries, leaves, and stems.The density of cyanogenic glycosides is higher in tea made from flowers (or leaves) than it is in berries.
The seeds of Sambucus callicarpa are poisonous and may cause vomiting or diarrhea”