Notes

The administration interface (and the code) sometimes refers to 'branches'. A 'branch' is any item in the Taxonomy, a Term or Vocabulary. Taxonomy Treemenu can build a menu from both terms and vocabularies. For a user, there is no difference.

On picking a branch

The root of a menu does not show.

Here is part of a taxonomy,

Now, let's say you want to build a menu based on the term 'cars'. You pick 'cars' as the root item,

The menu grown from cars will look like this,

If we showed the root item, the menu would look like this,

Which is rather stupid for navigation, as you already wanted cars. It is inefficient for the user, as they are not offered a choice on the first level. It is also visually inefficient, as a column of screen space has contains one item only.

Another way of looking at this; choose the term or vocabulary which 'contains' the root items you wish to show. In Taxomomy lingo, that means the parent of the base menu items.