Does anybody has a picture of Acer duplicatoserratum ? Must be really rare because there's nothing on Google...
Actually, Google is not comprehensive. Try other engines. International Plant Names Index contains this record. http://www.ipni.org/ipni/plantsearc...age=query_ipni.html&output_format=object_view
Trees small. Young branchlets glabrous or white villous-pubescent, glabrescent, glabrous when mature. Petiole glabrous or pubescent, geniculate at base, 1.5-5 cm; leaf blade orbicular, lanceolate-oblong, or subcordate, 2.3-10 × 3-10 cm, palmately 7- or 9-lobed, lobes lanceolate or lanceolate-oblong, both surfaces villous especially on veins, base cordate, margin sharply and doubly serrate, apex acuminate. Inflorescence corymbose, densely villous at first; peduncles 1-2.5 cm. Flowers small; pedicel 5-6 mm. Staminate flowers ca. 6 mm in diam. Sepals 5, slightly purplish, ovate-oblong or lanceolate, 2-3 mm, ± glabrous. Petals 4, white, orbicular-ovate, 1-1.5 mm. Disk into 4 glands. Ovary densely villous in pistillate flowers. Stamens short; anthers and filaments each ca. 1 mm. Nutlets strongly convex, 5-7 mm in diam., including wing 2-3 cm; wings spreading at obtuse angle. Fl. Apr or May, fr. Sep.
here are the photoes of my little seedlings. they are grown from seeds collected in taiwan the third photo shows the comparison of acer duplicatoserratum and acer palmatum.
I have attached some pictures of 2 seedlings of Acer duplicatoserratum. The seed was obtained in January 2009, sprouting in October. At the end of April 2010, one was over 50cm tall. Another with autumn colour is also shown.
Treated by the Flora of Taiwan under the synonym Acer palmatum var. pubescens. Try a search of images of that?
As indicated Acer duplicatoserratum is also known as Acer palmatum pubescens. As an amateur I find it difficult to work out the relationship of it to Acer ceriferum and Acer robustum which is now meant to be synonymous and Acer duplicatoserratum which some also may be the same species. My duplicatoserratum was grown from seed from Taiwan. The seed was small, similar in size to Acer sieboldianum. I also have 2 plants of Acer robustum grown from seed collected from China (not known from where). From memory it had quite large seed. In 10 years they have grown only to about 50 cm, the same as duplicatoserratum in one year. Though there are some features in common with there leaves, it is hard to see they are the same . Perhaps the Chinese duplicatoserratum is closer to Acer ceriferum which is also said to have small seed. Attached are some comparative close-up pictures of the leaves showing the pubescence which is common to them but also to several other species.
Simon, I share your confusion. Recently I have been looking at the descriptions of these maples on the Flora of China website and there seems to be no clear consensus between the authors as to which are separate species or synonyms. As listed, Acer duplicatoserratum is a separate species and Acer robustum is a synonym for Acer ceriferum. Alternatively one of the authors (Chang) considers A. duplicatoserratum to be synonymous with A. ceriferum and considers A. robustum to be distinct. (And that is without adding Acer linganense into the mix.) A. robustum and A. duplicatoserratum have been described by Peter Gregory in the Maple Society Newsletter within the last year, and with apologies to the author, to grossly oversimplify the descriptions, A. duplicatoserratum is described as similar to a hairy version of Acer palmatum (ssp. palmatum) and A. robustum is considered similar to a hairy version of Acer amoenum (Acer palmatum ssp. amoenum). This would agree with the seed sizes you described with respect to the pictured plants. (Just an amateur opinion, but hope it helps)
The authors of the Flora of China section on maples are recognized to be world authorities on the subject. If they cannot agree, then we, amateurs, cannot really add much...... I think a good practice for the forum would be (as you rightly do Maf) to recall the disagreement and list the options being seriously considered by the specialists. Gomero
A New Taxonomic Treatment for the Acer duplicatoserratum Complex (Aceraceae) in China and Taiwan Chin-Sung Chang and Kwang-Bok Woo, published 2011. (link is to a pdf) The authors argue that Acer duplicatoserratum, A. ceriferum and A. linganense should be treated as one species with A. duplicatoserratum being the accepted name. They also argue that A. robustum is distinct from A. ceriferum.
Than you MAF. As a non expert I tend to agree and think the best way to look at them as has been suggested is that ceriferum/duplicatoserratum are hairy "palmatum" and robustum are hairy amoenum for the reasons above including growth rates and seed size. I understand there are chemical differences between duplicatoserratum and palmatum though how well clarified those differences are between them all and even from one end of their ranges to the other is unclear. To add to the mix is Acer pauciflorum/pubipalmatum. I wonder how different it or ?they are as well. Simon
Just the other day I was looking at two established trees of Acer pauciflorum/pubipalmatum at Westonbirt Arboretum, and for me there is a clear difference in leaf shape and form between it and robustum and duplicatoserratum. I will post some pictures in the relevant thread when I have enough time, might be today, might not. Also, comparing robustum and pubipalmatum, the type of pubescence looks completely different. I haven't observed any established examples of duplicatoserratum to compare the pubescence of that to the other two.
MAF. Attached are some pictures of a seedling Acer duplicatoserratum (seed collected from Taiwan). These pictures were taken in late autumn (May 25th) in Australia and show the persistence of pubescence even on the small branches reminiscent of Acer pubipalmatum. Isolation on Taiwan would favour differences from other similar species. Hope these help for comparison. Simon
