from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
ARBOR CONSANGUINITATIS. A table, formed in the shape of a tree, in order to
show the genealogy of a family. The progenitor is placed beneath, as if for
the root or stem the persons descended from him are represented by the
branches, one for each descendant. For example : if it be desired to form
the genealogical tree of Peter's family, Peter will be made the trunk of the
tree; if he has two sons, John and James, their names will be written on the
first two branches, which will themselves shoot as many twigs as John and
James have children; these will produce others, till the whole family shall
be represented on the tree.