In article ,
P van Rijckevorsel wrote:

Beverly Erlebacher schreef
I've never seen "redcedar", only "red cedar", until this thread, FWIW.

As I noted above "redcedar" is a US term and has its stronghold in the
official documentation. In everything I have of the USFS (Forestry Service)
this is used, but my set of USFS-publications does not appear to extend
further back than 1948.

Government publications departments try to standardize their terms. When
I worked for the Ontario Geological Survey, I saw one of the geologists
in the elevator lobby one day looking exhausted. He had just come out of
a meeting in which an hour and a half had been spent arguing about whether
their publications should standardize on mudcracks, mud-cracks or mud cracks.
The most determined (or obnoxious) committee member tends to get his way in
these situations.

It is also in the field guides, both the Audubon and Peterson. Or to be
accurate: of the three Peterson guides, all by the same author, the modern
ones (Eastern, 1988, 1998 and Western Trees, 1992, 1998) use "redcedar",
while the old one (Trees and Shrubs, 1958, 1986) uses "red cedar". In
Western Trees the author notes that he would welcome Canoe-cedar instead of
Western redcedar.

And then conscientious private publications try to use the "standard" terms.
Meanwhile, ordinary people (and companies selling the lumber and products
made from it) tend to stick to older forms.

The average US-citizen uses "cedar" (when not used as a general category)
for Thuja plicata (western redcedar) and "aromatic cedar" for Juniperus
virginiana (eastern redcedar). The use of "cedar" is connected to the size
of the stands rather than to a particular tree.

Western red cedar is an important commercial species, widely used for
siding and outdoor applications like garden furniture, fences, decks
and utility poles. I don't know how big the two eastern species get
further south in their ranges, but up here (Ontario) they are small
trees, which make very knotty lumber. White cedar is mostly used for
fence posts and rails, and as a tall hedge or windbreak. A (white)
cedar swamp was once a big asset on a farm. I've only seen eastern red
cedar sold as short narrow boards for panelling closets, and maybe
small chunks for carving and other craft work, which you can hang in
closets or put in drawers to scent your clothes and deter moths.

I think I've only seen the term "aromatic red cedar" used in ads for
the lumber. I don't think I've ever heard it used in reference to the
tree.

Btw, in this climate, (white) cedar fence rails can last a century.

To call Thuja "arbor-vitae" goes back quite some time (perhaps long
enough for Mike Lyle's dictionaries to have captured usage? :^).

I see arborvitae (without the hyphen) used here mostly for cultivars used
as specimen trees or shrubs. The run-of-the-swamp forms are sold as
"cedar hedge" or "hedging cedars" by height, in quantities.

In Ontario, white cedar occurs both as dense pure stands in swamps, and
on very dry and shallow soils of abandoned fields. Eastern red cedar
is mostly found in the latter context, but almost exclusively around
the northeastern shores of Lake Ontario. You can see a lot of
virtually pure stands near Kingston where the soils are very shallow
over a Paleozoic limestone plain. Further north, and on the more
acidic soils overlaying Precambrian granites, it's white cedar all the way.