Sorry if my message came out in a too critical way. The good point (for genealogists) of the discussion in this thread was that German family names starting with T.n., such as Tann, Tan, Thon, Tannen, etc., may refer to the conifer tree or evergreen with needles, called "Tanne" or its plural Tannen.
Tannen are the most sought after Christmas trees in Middle Europe. They are not only beautiful but also rather rare. Colloquially many people call Fichten (spruces) and Föhren/Kiefern "Tannenbäume."
There is even the poetic expression "Tann," like "im Tann" meaning a forest that includes a noticeable number of mature conifers. Cassell's dictionary translates Tann to "pine forest," although it has only the translation "fir" when the individual tree is meant. Nevertheless, Edda Gentry's translation might pass muster after all!
The word fir (for Tanne) looks to me very similar to the German term Föhre (for pine). It even looks somewhat similar to Fichte (for spruce). Where, in German speaking lands is Föhre used for pine, as compared to the name Kiefer? In Austria, both terms are used interchangeably. "Tannhauser" could have been a surname for a family living in or at the border of a mixed forest. "Thonhofer" could have become the surname of a farmer who lived near a mixed forest, etc.