Figure 4

Partial taxon coverage. Shown is an example in which taxon coverage is not decisive for all trees, but it is decisive for 6 out of 15 possible rooted trees for 4 taxa. This is illustrated for the equivalent 15 unrooted trees, by taking advantage of the "trick" that there is an outgroup taxon, OG, that is common to both trees (a "reference taxon"), and thus we can regard it as the root. Then we can use known results [46] to determine whether the subtrees induced by the taxon coverage define the tree (and thus enumerate for which trees the coverage pattern is decisive).