I notice that Acer morifolium, mulberry leaf maple (for want of a better common name), is now leafing out in the garden. I am particularly enamoured of this southern Japanese species, having first seen young plants at Westonbirt Arboretum a few years ago. There, it formed a small tree of arching, willowy branches, the trunk glaucous-waxy and striped (and shaded conveniently by the outer branches), the twigs, buds and petioles scarlet. In the autumn, the leaves turn apricot and peach tones before falling. It is very much like A. capillipes, the red-budded snakebark in leaf, but ultimately, it is a much smaller tree, if one is to believe what's written about it (there isn't much). The maple literature is surprisingly scanty with respect to obscure species, and most people would be surprised how many Asian maple species are poorly characterized. But I digress... Acer morifolium and A. capillipes are easily confused when young, although there is considerably less wax on capillipes, and some of the major leaf veins of that species have peculiar tiny membranous flaps. Both share a broadly ovate leaf shape, 3 distinctly angular lobes and runnel-like veins. A number of other snakebarks are similar--A. rufinerve, A. tegmentosum, A. pensylvanicum and A. davidii subsp. grosseri. I'm always amazed that people assume they're looking at A. davidii when they're actually seeing the more commonly planted capillipes. Local (Vancouver area) nurseries grew it from seed for years and called it David's maple. Ah, but I digress again ... The Taiwanese A. rubescens is also leafing out now and is much like morifolium in bark and bud (I would be hard-pressed to distinguish them at this stage). The morifolium leaf shape seems to me halfway between capillipes and rubescens. Interestingly, a DNA (ITS) analysis performed recently at the UBC Centre for Plant Research on our entire snake bark collection (most of the species of Acer Section Macrantha) shows a very tight clustering of those species (capillipes, rufinerve (another Japanese species, with reddish hairs on the veins on the back of the leaves), morifolium and rubescens). It also showed that there are two distinct groups of snakebarks, but that's another story. I would be extremely interested to hear from other maple aficionados who are growing these species (they must be of documented origin). I'm particularly interested in seeing flowers from A. morifolium, as ours are not yet reproductively mature. The attached scan includes (clockwise from top): A. rubescens, A. morifolium, A. caudatifolium (in flower), A. rubescens and A. morifolium.
>Interestingly, a DNA (ITS) analysis performed recently at the UBC Centre for Plant Research on our entire snake bark collection (most of the species of Acer Section Macrantha) shows a very tight clustering of those species (capillipes, rufinerve (another Japanese species, with reddish hairs on the veins on the back of the leaves), morifolium and rubescens). It also showed that there are two distinct groups of snakebarks, but that's another story. < Acer rufinerve turned out to be closer to these others than AA. tegmentosum, pensylvanicum? I, for one, would like to learn the rest of the story.
Hi Douglas: Wada in Japan had this Maple back in the late 50's and probably had it earlier. Isn't Masayoshi Yano a member of the Maple Society? Possibly he can help with the flower question or contact the van Gelderen's at Esveld. I dont think there is a Westonbirt Arboretum web site for direct contact but I was told Hillier had this Mulberry Leaf Maple in his collection. I believe you may know of at least one person from the last reference. http://homepage2.nifty.com/chigyoraku/01spring2.html http://www.esveld.nl/htmldia/a/acmori.htm http://www.plantdelights.com/Tony/korea.html I agree with Ron, how about a follow up? Great job as it is, thank you! Jim
The other story (actually, there are a few more) is that the analysis clearly shows a split with the waxy-bark and non-waxy-bark snakebarks (that's the easiest way for me to differentiate them). In the first group, are A. caudatifolium, crataegifolium, davidii, morifolium, rubescens, tegmentosum, capillipes and pensylvanicum. The second group includes the closely allied pair A. micranthum and tschonoskii, and A. pectinatum and its segregates forrestii, laxiflorum, maximowiczii and taronense, and A. sikkimense. This species in the second group are generally more western (Himalayan) and northern (there is some geographical overlap with the waxier taxa). More analyses are to be performed before we get to near the bottom of this, but I'm pretty comfortable with this split. However, while we (at UBC) have a reasonably good collection of snakebarks, we still have not seen a few taxa from China. Many maples that have been described are not yet in cultivation and a number are reputed to belong in Section Macrantha; e.g., Maples of the World mentions A. laisuense as reportedly close to both A. tegmentosum and A. pectinatum (one or the other, not both, in my opinion). Acta Phytotaxonomica Sinica 21 (3) (1983) has Latin descriptions of two: A. caloneurum and A. huangpingense, the first supposed to be related to A. davidii and the second to A. maximowiczii (i.e., pectinatum). And in an article published in the Autumn 2000 Maple Society Newsletter 10 (3), You-sheng Chen describes in English a number of recently described maples from China, including A. brachystephyanum and (the similar) A. huangpingense. Unfortunately, the descriptions are not overly illuminating and the author neglects to mention where these plants have been collected. Let's hope they're still available to see in the wild.
Douglas, I have a very nice specimen of A. morifolium origin unknown (it was from a seed swap many years ago with the Maple society...perhaps you can track down the source?) My tree stands about ten feet tall... no flowers yet. Something you did not mention is the spring emergence. I find that the spring emergence is a very coppery color not like capillipies or rubescens. This lasts about 3-4 weeks before going into a deep green. thanks for the great info on morifolium, robert
Robert, I suspect your seed came from either the same seed that produced the trees I saw at Westonbirt or possibly from seed collected from trees in the Arboretum. One hopes that Peter Gregory (Maple Society President and formerly of Westonbirt), who knows such things, is aware of this discussion. In any case, you are right, the emergent leaf colour can be superb. I am not sure, however, that the coppery tones are unique to this species. One plant in our garden was quite red on emergence last year (temperature-related?), and I have seen A. capillipes specimens with similarly copper coloured foliage. Our accession is from Yakushima in extreme southern Japan, but the species evidently also occurs on the Ryukyu Islands, which extend nearly to Taiwan. Acer capillipes occurs just north of Yakushima and A. rubescens on Taiwan. I would expect some variation and introgression with overlapping species. Again, this is why it's nice to have collection data. Douglas
Hi, I didn't see any references of Acer morifolium on the GRIN website : http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?66 Maybe you should contact them to update their informations. Anyway thank you for all these details. By the way, I try to complete the Acer list page : http://www.ginkgo.biloba.online.fr/acer/especes/index.htm If you have some missing pictures, please let me know. Andre
Andre, Excellent web link! Thanks. With respect to updating official websites (such as GRIN), I prefer to wait until our analyses are more complete. I suspect that Acer morifolium may end up as A. capillipes var. morifolium (or something like that) as has been done by some authors in Japan.
Hi Douglas: Now, I better understand what you really want and why the documentation is important. Acer capillipes var. morifolium (yakushima-onaga-kaede) could very well be right. I can't help with photos of the flowers. I suspect your answer will have to come out of Japan unless Sir Harold Hillier kept notes on this Maple. I was told Sir Harold got his Maple from Wada back in the late 50's, about the same time frame that Don Kleim had some cutting grown plants come in. Don never called this one a species form but to him was a variety instead. If he felt that way, then others in Japan felt the same way also. http://www.inh.co.jp/~hayasida/E-repo18.html http://www-alnarp.stud.slu.se/~t6petlin/del1.htm Jim
Very interesting reading above. I have attached a picture of some seedlings from seed collected in an Osaka botanic garden in April this year. The tree (a typical "Snake Bark") was labelled as Acer insulare and said to come from Amami Oshima and Tokunoshima which are about halfway between Okinawa and Kyushu. In Japan it is also called Shima uri kaede in contrast to Yakushima onaga kaede which refers to Acer morifolium. In Van Gelderen's book both names are synonomous to Acer morifolium. The seed was still hanging on the tree at the end of winter and as a result germinated in 1 week are they more like morifolium or rubescens?
