Seabuckthorn or Hippophae( sandthorn,seaberry) is bush what produce orange fruits and they are very healthy and used for medicines. You can find this bush in Europe and Asia. And of course you can grow it in your garden worldwide.
For medicine you can use leaves fruits and seeds. But mostly people use fruits because you can make many things from them like jam,oil,alcohol production.
By the name of this berries i think they grow near water like sea,river,lake . At least i saw them in a wild many times near lakes, so seems because of it they got this name .
Did you saw this berries in your life? i know they are pretty common in former USSR ,Mongolia and Eastern Asia .