Yes, "antique" plant materials can be found on archaeological sites, and
should be recorded and/or retrieved and curated. Here in Delaware, there is
a cherry walk that was planted by the father of Caesar Rodney, the signer.
The walk is still there, back in the woods, in the form of new growth from
the old stumps. I  would not venture to guess how many genertions of cherry
trees have sprouted over the past 250 years, but the walk is a documented
eigheenth-century artifact that retains integrity. To the daffodil beds,
add yucca, lilac, pampas grass, osage orange, cultivated nut varieties, and
various imported mulberry species.  These plant materials are not only
durable indicators of buried archaeological sites, but they speak to such
intellectual movements as scientific farming and silkworm cultivation.
 
All about Iceland:       http://www.dmv.com/~iceland------------
Research and Land Rovers:http://home.dmv.com/~eheite/index.html
_________
|        \               BABY GETS 19 MILES PER U. S. GALLON!
|  BABY   \_===__
|  ___        ___|       Always remember to pillage
|_/   \______/   ||      BEFORE you burn.
___\_/________\_/_____                   ---- Ned the Horrible
Ned Heite  Camden, DE