Complex sentence: However, APG and APG II allow to segregate the Tetracentraceae, unplaced as to order and among the basal lineages of the eudicots.
Split into simpler sentences: However, APG and APG II do allow the option of segregating family Tetracentraceae, as an optional segregate. This family is unplaced as to order and left among the basal lineages of the eudicots.