Genealogist's diagram (4)
'genealogist's diagram' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tree that I've seen before include "Eg, laburnum" , "A number" , "Ash or elm, for example" , "Care for shoes" , "elder, maybe" .)
(Other definitions for tori that I've seen before include "doughnuts" , "rings" , "Large mouldings on columns" .)