I saw it( the phloem tissue stuff) in the implementation and assessment guide(in the section for unit 4).
BTW, if you noticed bio papers( chem and phsyics too) in edexcel are starting to test stuff not in the books or pat papers etc. Eg in th bio unit 4 paper one qs asked for 2 types of cells infected by hiv but the book only talks abt T-helper cells. Do you know where/how candidates are supossed to know this things. If you know any resources please tell me. Thks