Elderflowers may be found in a variety of locations—from parks to the roadside—but they aren't commonly sold in stores or markets, although they can be purchased online. Many people will set out to gather the flower heads once they learn where elderberry plants flourish and have bloomed flowers that are ready to pick. There are other white flowers that may appear similar, so make sure you know what you are looking for: a very large bush with clusters of white flowers and not small white flowers that grow directly out of the ground. Source: thespruceeats.com