I wonder why it's used. Because I know it is very hard to grow from seed. Maybe the understocks are acutally rooted cuttings. I've heard it can be rooted if you know what you're doing.

Well, mystery solved- Forestfarm made an error and sent me an Acer maximowiczianum instead of the Acer divergens I had ordered. I can't really complain, I have wanted one of these for awhile and it is a more expensive tree than the divergens.

Explains why it is grafted on Acer griseum; boy was I surprised when I came home from school and saw my Acer divergens had compound leaves :)

pteroceltis,
It looks like you have a bit more experience with this tree than I do. As you can see by my User Name, I'm a big fan of Acer griseum. Here's what I do know that may help you:

Seeds: Most seeds contain an embryo and hardly any endosperm to speak of. Another plant that shares this characteristic is the orchid. Understanding how the orchid propagates naturally by seed, I think, can help us understand how griseum does as well. The orchid bursts out millions of dust-like seeds on the forest floor. Those that land on a specific fungi will find the nutrients necessary for the seed to germinate. On their own, they do not have the CHO or the proteins to create roots or shoots. Likewise, griseum needs a food-source for germination. Also, the casing is extremely hard and thick. Scarification really isn't enough. It's a wonder that the tree has made it this far in evolution. Forgive me if you don't believe in evolution. Whether we came from a similar ancestor as the monkey or not, plants do adapt over time, and natural selection does occur. Anyway, some propagators have had success using this understanding and have almost surgically removed the embryos and placed them in a nutrient-rich petri-dish. The embryo germinates and we have a new plant.

Vegetative propagation: The general rule is, the younger the stem tissue, the more likely it will root. Seedling cuttings root pretty easily. But, seedlings are small and have very little stem to use. It's like a cycle: Take a seedling, cut it, root it, you now have another seedling. And, to get the original seedling, you have to get the seed to germinate. The trick we use is to almost force the well-established stock plant to succor: Hack it down low to the ground. Then, several immature stems come up. Then, use those to root. But, you have to let it grow green a little to continue to feed the roots. So, let one stem grow as a leader for the season.

Ok, that's griseum. But, the other plant you mentioned was cappadocicum. I will not pretend to be an expert on this plant. I know that it is related to truncatum; which easily hybridizes with platanoides (Norway). Is Norway not an aggressive weed up in your part of the country? So, my assumption - and sorry this was so long - my assumption is that Forestfarm used cappadocicum as a rootstock because of it's aggressive tendencies to your area. But, it is not as aggressive as platanoides. So, you have a rootstock that will be extremely successful in your area with an ornamental top.

Here's the concern: Maples are broken down into several groups. There really should be several genus' to break them down. Perhaps there will some day. For example, the Sugar Maple Group contains: Sugar, Silver, Red, Bigtooth Boxelder, Black, and some others. Japanese, for example, is not one of them. Nor is griseum. However, Boxelder is. Follow me here. The more related they are, the more compatible they are and the more likely the graft will take and last. I talked with a professor by e-mail at Penn State a few years ago. He was doing a test on graft compatibility of a Red scion and a Sugar stock. It looked successful for six years. During the seventh year, the graft split and the trees fell at the graft.

I don't know if griseum and cappadocicum are in the same group or not. I don't believe they are. However, Boxelder is trifolate and is in the Sugar group. cappadocicum is almost a webbed palm. As far as maples go, there isn't a more entire leaf that I've seen. It's the flower, fruit and seed that determines the relatedness, not the leaf. So, I'd ask Forestfarm just how long this union has lasted in their experience. Just because it took in the greenhouse and lasted a few years at the farm, does not mean it will last for a lifetime in someone's landscape.

I'm sorry if I confused or frustrated you. I just want you to understand why I would check with the grower their success on it. I'd hate your favorite tree to fall over one of the years during a wind storm. ericpaul

Maple hybridization generally is capable only between species and sub-species with the same series. For example, Acer rubrum and Acer saccharinium are in the series 'Rubra', and we have some very popular hybrids that have resulted from crosses between these two species (i.e. 'Autumn Fantasy')

Likewise, in the series 'Pamlata', we have wonderful crosses of A. circinatum (a N. American species), and A. palmatum (a Japanese species), such as A.p. 'Herbstfeur'. A. palmatum x A. shirasawanum hybrids are also becoming more common.

However, just because a maple belongs to a particular series does not guarantee its ability to cross with all other maples in that series. An example of this is A. japonicum x A. palmatum. To date there are no confirmed crosses between these two species, either natural or cultivated. It is likeley that there are factors which evolved over time to prevent these two species from hybridizing, as they share the same habitat in their natural environment. The reasons for developments like these are not entirely clear.

And what makes things even more interesting is that A.palmatum is always used as the rootstock for A. japonicum cultivars. In fact, A.palmatum is used as the rootstock for all commercially grown maples in the Palmata series. The incompatabilities seem to stop at sexual reproduction.

Regards,

K4

K4,

I really appreciate your comments. Is there a place that I can study these groups? Or, will you e-mail me so I can get some of this information from you?

Thank you,
EricPaul

Eric,

This link might prove useful, although its a little confusing because some scholars classify differently than others, or want to add more sub-species. Its broken out by region or continent:

http://web.archive.org/web/20070812014108/http://www.inh.co.jp/~hayasida/Ebunrui1.html

I created my own summary for the 'Palmata' series which combines all the species from all the regions, and you may want to do something similar for the series which interests you:

PALMATA Section, Palmata Series, Species and Sub-species are:

A.palmatum, A.matsumurae, A.japonicum, A.sieboldianum, A.shirasawanum, A.tenuifolium, A.circinatum, A.pseudosieboldianum, A.linganense, A.ceriferum, A.duplicato-serratum, A.pubipalmatum, A.pauciflorum A.changhuaense, A.robustum, A.anhweiense

Also, the book "Maples of the World", by Van Gelderen is considered the gold standard work on maples species. Its fabulous, if you're into that sort of thing...

Regards,

K4

I'm glad to see this thread rekindled. No worries about offending me with the evolution talk Eric; it would be very interesting to discover why some of the Maples in Section Trifoliata of Acer (i.e. A. griseum, A. maximowiczianum) have such difficulty with germination. There were two Acer griseum on the Syracuse University campus that I collected thousands of seed from for at least three years, and every single one of them was empty. Being dioecious, I'm guessing they lacked a suitable pollinator. And as you mentioned, the seedcoats are quite sturdy.

One little correction. You have Boxelder and Red Maple listed as being in the same section as the Sugar Maples. Bigtooth, Black, and Sugar (as well as Florida and Chalk) maples all belong in Section Acer Series Saccharodendron. European botanists generally state that the only species in the group is Sugar Maple with the rest being subspecies of it. While admittedly not an evolutionary biologist, I have encountered (and have in my plantings) all but the Bigtooth and personally disagree. What appear to be Sugar Maples from a distance are the most dominant species in my woodlands. A closer look reveals that the trees are about 60/40 Sugar/Black, with each species being quite distinct from the other. A nearby abandoned lot is being heavily pioneered by Maple seedlings, some of which are definitely hybrids between the two, but for the most part the trees are very easy to differentiate once familiar with them. As for the Red Maple, it occupies a spot in Section Rubra with only the Silver Maple and the very rare Hananoki Maple (A. pycnanthum) from Japan. Plantsmen have discovered that it can be used as understock for a wide range of maple species, however. I have heard of Section Palmata species being successfully grafted upon it. As you noted, long-term compatibility is questionable.

As for the Boxelder, I'm not a big fan of it (is anybody :) It does have its place, and I did recently plant a variegated cultivar, 'Elegans', so I guess I can't really talk too bad about it. It is in Section Negundo and is quite distinct from most other Maples. Its closest relatives are beleived to be the Ivyleaf and Henry Maples (A. cissifolium and A. henryi). Google these. I have the Henry and it is spectacular, especially in autumn. Its leaves look similar to Poison-Ivy and I must admit to scaring a garden guest or two with it. There are some interesting papers out there on Boxelder genetics and its relationships with other Sections in Acer.

Back to the original topic, I have planted the grafted plant from forestfarm so that the union is buried in the hope that the Acer maximowiczianum scion will root on its own. With both species being relatively slow growers, I am hoping to avoid the scion-understock growth size differential which often leads to the breaking you described on the Red/Sugar graft. I have heard of good success with this type of griseum/nikko graft before though, so I'm optimistic.

As a side note- have you ever heard of the cross between the Sycamore Maple (A. pseudoplatanus) and your cherished Paperbark? Being from two entirely different sections in Acer, it seems impossible. According to an old thread on the UBC Maples forum however, it has been confirmed by genetic testing in Europe. I procured one from Forestfarm a year ago and it has been a strong grower with deeply lobed leaves (bright purple undersides) and good red/orange fall color. I highly recommend it.

As K4 noted, "Maples of the World" by van Gelderen is outstanding and will give you some great insight into the genus. It is a bit dated however, and some new species have been discovered and/or introduced to western horticulture since its publishing. I have a decent collection of species maples (Only one seedling Japanese Matsumurae-no cultivars yet) and would be glad to share some of my experiences with you, as well as where to find some of them, as it can often be tough.

I wonder if anyone knows whether one could graft a Japanese maple onto a big leaf maple? On our property here in the PNW acer macrophyllum grows like a weed.

For pteroceltis, I have a few questions if you don't mind.

First, how is that A. maximowiczianum doing that Forest farm sent you by mistake, and how does the fall color compare to some of the other trifoliates?

Second, now that you have had it a few years, what can you tell us about the a. griseum x pseudoplatanus hybrid?

And third, I was intrigued by your user name. It makes me assume you have experience with it, so I must ask, how does Pteroceltis perform for you in your area, and should I be placing and order for it from forest farm?

Thanks in advance.

For buckeye,

First, the A. maximowiczianum is doing alright, putting on about 6" per year. I don't have it in the best soil though, and I think that might be slowing it down. It's part of a personal experiment to see which of the trifoliate maples can handle limestone soil (this is one is decent; A. mandschuricum and A. triflorum are epic failures). Fall color has been a mix of yellow, orange, and red- often in the same season.

Second, the Acer hybrid has started to really take off. The leaf undersides are a striking violet, and the fall color is a lot like the A. maximowiczianum, if a bit less intense. The leaves are like a cutleaf Sycamore Maple, and you can definitely see the influence of the trifoliate parent species. Maybe it's my imagination, but the bark loks like it is starting to shred very slightly.

Third, I have grown a small Pteroceltis seedling in an exposed, rocky, poor soil area for about 5 years and it has only gone backward (but alive). This year I will be moving it to a much better site so I can have a better idea on it's adaptability in upstate NY's zone 5/6 here in the finger lakes. The large plant at the Morris in Philadelphia made me a believer! If you plug Pteroceltis into google images you can see it for yourself. For the price of a tube plant at Forestfarm, I would say give it a shot!

Thank you pteroceltis. I appreciate the info. I may have to order a Pteroceltis and one of the Acer hybrids. The only A. pseudoplatanus I have tried here in northern Ohio is 'Esk Sunset', which is beautiful, but has been painfully slow.