Joseph was a son of the House of David, therefore he was, in Old English, a “scion” of David. Means he was descended from David via one of David’s sons (or possibly a daughter, though usually traced on through the male line). Since Solomon had a couple hundred concubines, chances are good that David had several hundred male grandchildren, though only those born of his wife or wives (rather than foreign concubines) were eligible to be considered in the descent of the kingship and therefore of the Royal Line directly. Jews consider that religion is descended through the woman, but inheritance through the man.