They are very likely both A. columnaris. True heterophylla is very rare in the U.S. (except in California). Here in Florida, i know of one 2 or 3 true heterophyllas in the landscape, but thousands of columnaris. I have never seen true heterophylla for sale anywhere but in CA. They are easy to tell apart when freshly germinated and also older. This age is more difficult.

I think the upper branches on the second one are simply in a more juvenile state...as they mature, they will adopt the more feathery habit seen in the first photo.

From Krussman (Manual of Cultivated Conifers, 1985):

A. columnaris: Tree, to 60 m high, the lower branches usually abscising, short shoots arise from the adventitious buds at the base, this portion of the stem is then densely covered to make a "green column", branches horizontal, side branches long, slender, whiplike in appearance, bark exfoliating, paper thin...Differing from the similar A. heterophylla in the compact, less "feathery" habit and the columnar, "green stem."

So A. columnaris is the novelty potted x-mas trees they sell everywhere this time of year...?

Questions... are these trees seed grown? And why are there 4 or 5 trunks in these pots they sell? Multiple seeds?

Thanks for the responses so far. So for all of these they have been selling A. Columnaris under the wrong name in the trade? A. Columnaris is Cook Island Pine, but they are always labeled "Norfolk Island Pine".

Not really sure about the upper branches on the second photo being more juvenile than on the first, except maybe for the very top row of branches. Even the older branches on each plant appear very different, and the needles on the one in the second photo appear to be more tightly packed. The two are about the same height, the trunks are about the same caliper and I would think the trees are about the same age. Of course no way of knowing for sure.

Could growing environment impact the look of them that drastically as to where they look this different? I'm asking because I don't know. I know some plants have extremely different growth habit when given different growing environments. Like Dracena have much more stiff, straight, sword like leaves in direct sun light, but when grown in shade the leaves are much more graceful and arch/ bend downwards. Could this be something similar going on here if they were each grown under different light / environments?

As to the question about multiple plants in multiple pots I think that is a function of the growers shoving multiple seeds into the same pot, quite possibly to save money and to also achieve a fuller looking plant. Kind of like they do with Parlor Palms (Chamaedorea Elegans).

I think time will tell with your two trees. Two distinguishing hallmarks of A. columnaris are 1) flaky, exfoliating bark, and 2) a tendency to form a slight "S" curve towards the base of the trunk.

Yes, A. columnaris is sold everywhere as 'Norfolk Island Pine'. True heterophylla is very rare in the trade and it can be distinguished also by the much larger cotyledons, flat, longer branches held at more regular and distant intervals on the stem. At maturity, A. heterophylla looks much different being much more open and much wider in crown.

The reason they are "multi-stemmed" is because the growers plant several together in the same pot for "Christmas trees" or houseplants and then they get planted outside as clumps of trees.

Growing conditions (especially light) greatly impact how cultivated trees look. The top photo looks like it has been in more shade and the bottom one looks like it has been in full sun.

Also, the scales along the trunk of A. heterophylla point upwards and those on A. columnaris point downwards.

"true" A. heterophylla

A. columnaris (what is mistekenly sold as "Norfolk Island Pine")

Thanks for all of the replies to this thread so far! While there is lots of helpful info here, I still am unsure of what I have.

eric_9b, the scales on the trunks of mine point both up and down. Just depending on the section of trunk they are on. So I'm not too sure how much of a key that feature of the plant is in its true ID. So it is still confusing as heck. On the plant in the second photo I posted there are many more pointing upwards than downwards, but the growth looks more like A. Columnaris to me, than in the one in the first photo I posted. On the plant in the second photo of mine, that one's growth habit looks more open like A. Heterophylla, however on that plant the scales are about evenly split between pointing up or down.

I guess really there is not much way to tell for sure on young plants. I just thought I might have one of each since the growth habits on two that I have are very different from one another. Again though, I suppose that could be due to different growing environments including light levels.

To clarify, the tree in the second pic was recently bought, and looked like that when you bought it? This new tree was probably grown outside in the sun and wind, which makes a difference. Out of the wind and direct sun the branches are weaker and more droopy, I believe with woody plants in general.

Noki, yes, your clarification is correct. However I still don't think that the trunk needles or scales are a good key to positive ID given my reasons above.

"eric_9b, the scales on the trunks of mine point both up and down. Just depending on the section of trunk they are on. So I'm not too sure how much of a key that feature of the plant is in its true ID"

On Eric's pics, the A. heterophylla has all its needles pointing up, while his A. columnaris has a mix, most pointing down but some level, some pointing up. So if yours also has a mix, suggests it is more likely A. columnaris.

Resin

not sure if this has been suggested yet, but I just got a lovely one of these (Norfolk Island or I guess really Cook Island Pine) from Home Depot for $15 - on xmas sale :) Good luck!

The first photo is of a Norfolk Island Pine, the second is a Cook's Pine. They are , indeed, different species. The Cook's Pine is somewhat heartier and grows taller. Neither has any resistance to the cold.

Neither has any resistance to the cold.
Not exactly. There's a "Norfolk Island pine" of at least 20'-25' on the Isle of Brissago in Lake Maggiore, Switzerland. This extraordinary 9b/10a climate has winters averaging roughly as cool as Seattle's or Richmond, VA's in terms of daily mean - and with more snow than either - but hardly ever dipping much below 30F. I have seen it myself, as have many European rare plant collectors, and it's definitely not a monkey puzzle.

The island also has coffee bushes, a 100' Eucalyptus, Phoenix canariensis of course, various Citrus, and many South African plants like Aloes, Ericas, and Proteas. There are huge clumps of Australian kangaroo paws. It's truly surreal to see these plants with a snow covered alpine backdrop.

I do think it is more to environmental acclimitation of the Araucaria heterophylla. The first pic was probably acclimitised to partial shade and that the second photo was just recently been moved indoors which was probably grown outside.. First photo appears to be more heterophylla because it is more spaced compared to the second photo which appeared to more bushy, fuller and compact. Mine looks like this.... which I truly believe as A. Heterophylla...acclimitised to indoor bright lights..

Yes, the thinner, flatter more fern-like growth would be the younger type of foliage and the more dense and up-swept the more mature.

True norfolk island pine have large spacing between branches and are symmetrical. Their needle like foliage on the branches are also long a narrow. Btw... you can buy them in stores during holidays. They are frequently mixed up but we do have one that is a true Norfork island pine bought at meijer. Another helpful tip is the branches along the main terminal come out growing upward and then may level out or droop. The cook's branches immediately grow outward or downward. N. Island pine are also known for the dark green foliage and less peeking bark as they are not actual pine trees but are tropical.

First photo is of our norfolk. It is 4-5years. Sunburns easily in direct sun. Needs high humidity otherwise drooping like this occurs. It recently changed locations due to a move and is not happy.

Second photo is foliage. The top foliage is a cook and the second foliage is a norfolk island. I hope this helps.

Notice the growth toward the terminal is more bare. This is a norfolk island pine.