View Full Version : Are All Trees Flowering Plants?
tofu
2007-May-03, 10:35 PM
Possibly a stupid question. Are there any trees that don't produce flowers? The common ancestor of trees was a flowering plant, and since flowers work so well, I'm wondering why a tree would give that up
Peter Wilson
2007-May-03, 10:47 PM
When biologists use the word "flowering," they really mean, "produces seeds" as opposed to "produces spores." So if you mean "flowering" in the biologist's sense of the word, Yes: all trees produce seeds...not spores.
But when Common Man uses the word "flowering," it means produces an attractive lure which is visited and pollinated by insects and birds (as opposed to wind). So if you mean "flowering" in common sense of the word, No: some trees do; some don't.
:neutral:
Delvo
2007-May-03, 11:12 PM
No. Botanically, "flowering" only refers to the reproductive process and structures of angiosperm plants, which excludes the gymnosperms. Gymnosperms have seeds, but those seeds are produced in cones, not flowers/fruits.
Gymnosperm trees include pines, firs, Douglas-firs, spruces, cedars and several other non-cedars that are commonly called cedars anyway, junipers, yews, redwoods, sequoias, cypresses and some others with "cypress" in the name like baldcypress, ginkgoes, larches, cycads, and probably a few others I'm forgetting.
Anything else that gets to "tree" size today is a flowering plant. To be more specific, of the two main groups of flowering plant, dicots and monocots, they're almost all dicots. Most monocot species are not trees but grasses, grains, and sedges. The only members of the group that get big enough to be called a "tree" are the palms (including palmettos), whose trunks are essentially just beefed-up persistent grass stems, which is why they seem so different from other trees.
Dicots account for all of the rest in the modern world, which is far too many types to name all at once without a written list. Essentially, it's nearly any all kinds of tree that I didn't already name above.
Ferns are said to have once gotten up to 30 feet tall, but those kinds of fern aren't around anymore.
trinitree88
2007-May-03, 11:29 PM
No. Botanically, "flowering" only refers to the reproductive process and structures of angiosperm plants, which excludes the gymnosperms. Gymnosperms have seeds, but those seeds are produced in cones, not flowers/fruits.
Gymnosperm trees include pines, firs, Douglas-firs, spruces, cedars and several other non-cedars that are commonly called cedars anyway, junipers, yews, redwoods, sequoias, cypresses and some others with "cypress" in the name like baldcypress, ginkgoes, larches, cycads, and probably a few others I'm forgetting.
Anything else that gets to "tree" size today is a flowering plant. To be more specific, of the two main groups of flowering plant, dicots and monocots, they're almost all dicots. Most monocot species are not trees but grasses, grains, and sedges. The only members of the group that get big enough to be called a "tree" are the palms (including palmettos), whose trunks are essentially just beefed-up persistent grass stems, which is why they seem so different from other trees.
Dicots account for all of the rest in the modern world, which is far too many types to name all at once without a written list. Essentially, it's nearly any all kinds of tree that I didn't already name above.
Ferns are said to have once gotten up to 30 feet tall, but those kinds of fern aren't around anymore.
Delvo. There are some tree ferns at ~ 80 feet.http://www.virtualoceania.net/newzealand/photos/flora/ferns/pete
Delvo
2007-May-03, 11:32 PM
The common ancestor of trees was a flowering plantThis is not accurate. The common ancestors of flowering trees were flowering, but the common ancestors of fern trees and cone-bearing trees never had flowers. "Tree" is just a description of size, not a taxonomic group, and large size has been invented multiple times by unrelated plants... just like the phrase "big animals" (or its single-word equivalent, "megafauna") would include lots of unrelated animals that only had to have one thing in common: being big.
Peter Wilson
2007-May-03, 11:38 PM
No. Botanically, "flowering" only refers to the reproductive process and structures of angiosperm plants, which excludes the gymnosperms. Gymnosperms have seeds, but those seeds are produced in cones, not flowers/fruits...Technically, that is correct, but my point is the common ("Buy her some flowers...") and scientific meaning are at odds, and the scientific definition is confusing, hinging--apparently--on whether the seed is in an ovary or not :confused:
So what's an ovary? Now we need a definition of "ovary," because they don't mean an "ovary" like the ovary in the woman you just bought flowers for.
It never ends...
Nereid
2007-May-04, 02:24 AM
No. Botanically, "flowering" only refers to the reproductive process and structures of angiosperm plants, which excludes the gymnosperms. Gymnosperms have seeds, but those seeds are produced in cones, not flowers/fruits.
Gymnosperm trees include pines, firs, Douglas-firs, spruces, cedars and several other non-cedars that are commonly called cedars anyway, junipers, yews, redwoods, sequoias, cypresses and some others with "cypress" in the name like baldcypress, ginkgoes, larches, cycads, and probably a few others I'm forgetting.
Anything else that gets to "tree" size today is a flowering plant. To be more specific, of the two main groups of flowering plant, dicots and monocots, they're almost all dicots. Most monocot species are not trees but grasses, grains, and sedges. The only members of the group that get big enough to be called a "tree" are the palms (including palmettos), whose trunks are essentially just beefed-up persistent grass stems, which is why they seem so different from other trees.
Dicots account for all of the rest in the modern world, which is far too many types to name all at once without a written list. Essentially, it's nearly any all kinds of tree that I didn't already name above.
Ferns are said to have once gotten up to 30 feet tall, but those kinds of fern aren't around anymore.(my bold)
Let's not neglect cycads (http://en.wikipedia.org/wiki/Cycad)!
Delvo
2007-May-04, 03:46 AM
the scientific definition is confusing, hinging--apparently--on whether the seed is in an ovary or not :confused:
So what's an ovary? Now we need a definition of "ovary," because they don't mean an "ovary" like the ovary in the woman you just bought flowers for.Actually, it is the same. It's the body part where meiosis occurs and egg cells (ovum/ova) are produced. The defining difference between angiosperms and gymnosperms is that it surrounds and encloses the seed(s) in angiosperms (which means "contained/enclosed seed") and has an opening that partially exposes it/them in gymnosperms ("naked seeds").
Yes, "sperm" means "seed", and the cells that become seeds in plants are biologicall "egg cells" or "ova"... which means that once a plant ovum/egg cell is fertilized, it becomes a seed, which is "sperm"... let's just not think too much about the analogy for trees releasing lots of pollen into the air...
Yes, "sperm" means "seed"...
[dripping sracasm] Oh, gee, thanks for that. [/dripping sracasm]
We have a live oak in our front yard. For those not familiar with the species, it's called "live" oak because the leaves stay green and on the tree through winter. But in spring, the leaves drop, the tree flowers (small, but noticeable if you look), seeds are started, and new leaves bud out.
Between those last two steps, the tree drops all the "fluff" that was made during the flowering and pollinating process. The "stuff" covers the ground, coats the roof, fills the gutters... a mess.
And in my mind I tell myself, I know what this is, but I'd rather not think about it.
Thanks for the reminder. <--- more dripping sarcasm
BTW, isn't it as simple as deciduous trees (those that drop their leaves seasonally) flower, evergreens do not?
Ronald Brak
2007-May-04, 01:54 PM
I remember a Japanese movie translation getting screwed up on this point.
BioSci
2007-May-04, 03:29 PM
Yes, "sperm" means "seed", and the cells that become seeds in plants are biologicall "egg cells" or "ova"... which means that once a plant ovum/egg cell is fertilized, it becomes a seed, which is "sperm"... let's just not think too much about the analogy for trees releasing lots of pollen into the air...
Well, one of the latin meanings for "sperm" is seed - but under current English botanical meaning: "sperm" refers to the male pollen not to the resulting fertilized seeds.
(And actually "sperm"is typically reserved for seedless plants such as mosses that do have motile "sperm cells" that swim to the female egg in a layer of water. In seed plants the male "sperm" is more properly called pollen.)
Delvo
2007-May-04, 04:09 PM
Thanks for the reminder. <--- more dripping sarcasmDripping, eh?
BTW, isn't it as simple as deciduous trees (those that drop their leaves seasonally) flower, evergreens do not?No. As was just pointed out, some oaks, which are flowering plants, keep their leaves all year, which makes them evergreens. (And there are plenty of others, especially in tropical and subtropical climates.) And a few non-flowering plants, like ginkgo, are deciduous.
This is a pattern that usually holds, but not always, so it's not a usable rule.
Dr Nigel
2007-May-04, 04:25 PM
I remember a Japanese movie translation getting screwed up on this point.
Careful! You're moving into a minefield of multiple meanings!
Nereid
2007-May-04, 04:41 PM
Are (fully) aquatic plants gymnosperms? angiosperms? something else??
How closely do large aquatic plants resemble trees?
BioSci
2007-May-04, 05:44 PM
Are (fully) aquatic plants gymnosperms? angiosperms? something else??
How closely do large aquatic plants resemble trees?
Most aquatic "plants" are angiosperm, very few gymnosperms (any?) and a few non-seed plants - moses, ferns, worts... Many such flowering plants float on the surface and have very limited root systems.
The really large "kelp forests" are marine algae and not actually "plants."
Disinfo Agent
2007-May-04, 09:20 PM
Are (fully) aquatic plants gymnosperms? angiosperms? something else??
How closely do large aquatic plants resemble trees?I'm not sure what you mean by "aquatic plants". Algae are definitely not gymnosperms or angiosperms. In fact, these days they aren't even considered plants!
Perhaps you asked because of the reference to the swimming sperms, above. Well, that's the funny thing: they use moist and rain to swim through, IIRC... :)
No. As was just pointed out, some oaks, which are flowering plants, keep their leaves all year, which makes them evergreens.
If you mean my live oak reference, they do drop their leaves in the spring, which makes them deciduous (seasonal leaf dropping). Are their oaks which are truly evergreen?
Delvo
2007-May-05, 04:06 PM
"Evergreen" and "deciduous" isn't just about whether there's a season when the leaves die and fall off; it's about whether there's a time when the tree has dropped all of its leaves at once and gone bare. Pines and spruces and such drop their leaves at a certain time of year, too, but they're evergreen because they keep some even while others fall, and each individual leaf sticks around for multiple years instead of a fraction of one. (If the persistence is usually three years, for example, then the dropping it does each year is only about a third of the total; if it's five years, a fifth of the total gets dropped per year...)
Deciduosity is mainly an adaption to winter, so evergreenness gets more common the warmer the climate is, even in families that are usually deciduous in colder climates. For example, southern magnolias are evergreen, but one of their closest relatives, the "tuliptree" or "yellow-poplar" or "tulip-poplar" (Liriodendron tulipifera, which is neither a tulip nor a poplar), lives farther north and is deciduous. And the holly genus includes both evergreen species (Ilex opaca) and deciduous species (Ilex decidua). The same goes for oaks. I'm not sure, but in the tropics, there might not even be ANY deciduous plants, since there's no real winter.
Dr Nigel
2007-May-05, 04:35 PM
...
Deciduosity is mainly an adaption to winter, so evergreenness gets more common the warmer the climate is, even in families that are usually deciduous in colder climates. For example, southern magnolias are evergreen, but one of their closest relatives, the "tuliptree" or "yellow-poplar" or "tulip-poplar" (Liriodendron tulipifera, which is neither a tulip nor a poplar), lives farther north and is deciduous. And the holly genus includes both evergreen species (Ilex opaca) and deciduous species (Ilex decidua). The same goes for oaks. I'm not sure, but in the tropics, there might not even be ANY deciduous plants, since there's no real winter.
Interesting.
As you go further north still, deciduous trees give way to evergreens (I'm thinking of the large fir and pine forests of Scotland and Scandinavia here); when winters include heavy snowfall and very little daylight, the evergreens seem to have the advantage.
Delvo
2007-May-05, 04:37 PM
That's because needles work better for winter than broadleaves... which is why it's generally the broadleafed trees that go deciduous and the needle-bearers that don't. :)
hhEb09'1
2007-May-05, 06:32 PM
one of their closest relatives, the "tuliptree" or "yellow-poplar" or "tulip-poplar" (Liriodendron tulipifera, which is neither a tulip nor a poplar), lives farther north and is deciduous. It's called a tulip tree, of course, because its leaves have the shape of a tulip flower.
And the holly genus includes both evergreen species (Ilex opaca) and deciduous species (Ilex decidua). The same goes for oaks. I'm not sure, but in the tropics, there might not even be ANY deciduous plants, since there's no real winter.But there is drought. This wikipedia article (http://en.wikipedia.org/wiki/Tropical_and_subtropical_dry_broadleaf_forests) mentions large tropical dry forests, in which deciduous trees predominate.
Dr Nigel
2007-May-06, 12:03 PM
...But there is drought. This wikipedia article (http://en.wikipedia.org/wiki/Tropical_and_subtropical_dry_broadleaf_forests) mentions large tropical dry forests, in which deciduous trees predominate.
That's a good point. Firs and suchlike tend to be very thirsty.
eburacum45
2007-May-07, 04:20 PM
Long ago in the Carboniferous period no trees were flowering plants, because they hadn't evolved yet. Instead you had giant horsetails and club mosses, which today are small and relatively insignificant 'cryptogam' plants which dont even bear seeds as such.
tofu
2007-May-08, 10:05 PM
Sorry to have abandoned the thread - I got buy at work, but I promise that I'll never again let work get in the way of BAUT. lol.
So, it sounds like Gymnosperms evolved into the familiar tree layout first, and then flowering plants evolved to that through convergent evolution. Very interesting stuff. It also answers the question I had about why a plant would give up flowers, since flowers work so well. The answer is, they didn't!
JESMKS
2007-May-08, 11:03 PM
There is also Tamaracks (Larix), a needle bearing conifer that is deciduous in that it drops all it's needles in winter.
Ivan Viehoff
2007-May-09, 02:44 PM
As you go further north still, deciduous trees give way to evergreens (I'm thinking of the large fir and pine forests of Scotland and Scandinavia here); when winters include heavy snowfall and very little daylight, the evergreens seem to have the advantage.
It ain't necessarily so. Clearly coniferous spruce dominates the extensive nordic forests of North America, Siberia and Scandinavia. However conifers are not always the hardiest. In the far south of south america, the native southern beech species predominate the southern forests. In many places it is evergreen southern beech species (coigue) which predominate, but the hardiest, predominating forests in Tierra del Fuego and growing closest to the tree-line, is deciduous Nothofagus antarctica. In the far north of Scotland, Scots Pine won't grow but you'll find birch and willow in areas where the native conifers won't grow. (Though exotic sitka spruce plantations can also be found in those areas.) In Iceland and Greenland there are no native conifers, but birches and willow are native. I would expect that even in Siberia and North America you will find willows growing further north than the limit of spruces. The most northerly growing plant is a willow, albeit a prostrate one you might not call a tree.
Kullat Nunu
2007-May-09, 05:51 PM
Yeah, at least in Europe some birch live further north than pine or spruce.
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