I don't think so. Ephedra is a conifer but not what I think of as a tree.

Pinus culminicola and P. pumila are conifers but usually shrubs.

Plenty of junipers are shrubs, too.

Even more so, Lepidothamnus fonkii (Podocarpaceae; from southern Chile). A conifer which doesn't get over 30cm tall, and can produce cones when 7cm tall/wide.

Resin

There are fossils from the Mesozoic Era of herbaceous conifers. Sadly, they don't exist any more.

Resin

Lots of prostrate or groundcover forms of conifers that could not in all honesty be termed "trees". The arboricultural definition is "a woody plant with a single trunk and a distinct and elevated crown". I guess 'elevated' is open to some interpretation but it's tough to consider anything less than several feet much of an elevation :-)

I'm sure that I've never seen Microbiota decussata in tree form.
One cannot use the terms always or never when discussing plants, there are too many exceptions to the rules that we make up. Where is the fallacy in the following:
"All conifers are woody, cone-bearing plants, all woody, cone-bearing plants are conifers."
Sam

Is this just a value judgemnet on what woody plants count as a tree? What is a tree then? Microbiota is not a tree because it grows so low? Sounds like some sort of prejudice.

So what Conifers were there...? Conifer weeds? Conifer annuals? Non- woody conifers that were perenials? Probably not any conifer seaweed thou.

What the heck grew in "grassy" areas before grass evolved? There had to be something on the praires 150-200 million years ago.

Definition: a tree is a plant capable of reaching at least 6m high at maturity, with secondary branches supported on a single main stem or trunk.

Note "capable of" - a young sapling less than 6m can still be called a tree, as the expectation is that it will reach 6m or more at some time in the future. Also when dealing with a species, to be called a tree, all that is needed is that at least some individuals will match the criteria (a species which only rarely does so can be described as "a shrub or occasionally a small tree").

"All conifers are woody, cone-bearing plants, all woody, cone-bearing plants are conifers"

Yes, I guess so, as long as you don't include structures which are not cones but do resemble cones (e.g. alder catkins), and bear in mind that some true cones (e.g. those of yew and podocarps) do not resemble 'traditional' cones.

Resin

Ken, all Maples are Maples but not all Maples are trees (6 meter rule). However... some little dwarf Acer palmatum growing an inch a year will be 6 meter someday, someplace.

Bear in mind.....

Dax

oh thank god.. i thought you all left us .... the forum has been so dead .. i feared i was alone in my cyber conifer garden ...

sooo ... tree is basically defined by its height and branch structure ... put simply ...

if a momma is some giant.. say picea abies ... but there is a true .. one inch a year mini .. is it still a tree even though it might take it 300 years to get to 6 meters? .. too early for me to do conversions and multiplication .... just work with the example, please.. in other words .... it has, as dax notes, the eventual potential to reach the height requirement ... in someones lifetime ...

or ... if momma is truly a tree .. can she produce a shrub from a witches broom???

i know it all comes down to semantics .. and the definition of terms .... but i am thinking about all the posts we get from newbies.. and trying to come up with some very simple ideas of how to communicate various ideas to them ... e.g. trees and shrubs [leaving aside various swamp trees] should be grown like trees ... as compared to perennials and annuals ... P & Annuals need constant moisture and a lot of food, whereas trees .. after 'establishment' [for the most part] need high drainage and low fertility soils to do well .... in other words.. you will kill a tree with too much love ... love defined as too much water and too much food ...

ken

Value judgement? I don't think so. There are accepted definitions for these terms, just as there are accepted definitions for anything else. I've never encountered the specifics of Resin's definition before - 6m seems a bit arbitrary, as does the ISA's definition: "a woody perennial usually having one dominant trunk and a mature height greater than 5m". I guess that removes true dwarfs with tree-like growth habits (clear trunk, elevated crown) like a number of conifers and Japanese maples from the 'tree' category. And how does that impact multi-stemmed or multi-trunked "trees"? What do we call these? I find terms like 'tree-like shrub' or 'shrub-like tree' less than satisfactory, personally.

When I was attending horticultural college, the definition we learned was that a tree was woody perennial with a distinct trunk(s) and an elevated canopy or crown generally exceeding 15' at maturity, not including dwarf forms. A bit cumbersome to be sure but it seems to cover all the bases.

I guess while my back was turned, the bar was being set higher. When I was a student -- and that phase lasted decades -- the height to be considered a tree was 13 feet. Some said 12 feet, but nobody pushed the limit to 6 meters regardless of the measurement system in vogue. And a usually single stem. All else were s h r u b s and doomed to lives of underclass iniquity,unequity, and quiet desperation well deserved.

I'll comment even further that Ken's "conifer" question involves dwarf forms. Simply stated, some forms whether from withces' broom origin or seedling grow very slowly, and as a "shrub" but only to sometime develop a leader.

A perfect example rests right in Ken's neck of the woods at The Harper Collection. Picea omorika 'Nana' - Chub Harper upon discussions I believe told me that the "bulk" was planted during the mid-sixties which makes the collection to be 40 years. Coincidentally, we cultivar folks on this forum know this to be a shrub for many years of it's life. Same is true for a tree-like shrub such as Picea abies 'Will's Zwergform' which is actually defined as 'being tree-like' however, growing slowly (approximately 3" per year) and thus by another whole set of rules as defined by The American Conifer Society - as being a dwarf I'll say it Ken, "Go figure." In the Harper Collection and as these decades have passed, a magnificent 'Nana' Picea omorika has grown to be at least 15'. A shrub that becomes a tree...

So maybe with a hint of philosophical word-play, and with consideration to everyone's defined above definitions from above and other expressed notions of sorts, but now adding a new element, "time" to the equation - we now have a "tree/conifer" that has shown us it can change from a shrub, that it can grow a dominant leader as a result of genetics... and thus allowing Ken's statement to have partial trueness.

Me, I'm a pruner, so beware! lol What was "three clumps now is one!"

Later,

Dax