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The Wynkcoombe Arboretum
Dan Crowley (2020)
Crowley, D. (2020), 'Acer longipes' from the website Trees and Shrubs Online (treesandshrubsonline.
A deciduous tree to 10 m in the wild. Bark grey to purplish-grey. Branchlets glabrous, green, turning grey to brown and woody only after several years. Buds, ovoid, with 5 to 8 pairs of imbricate scales. Leaves narrowly pentagonal in outline, base subcordate, 3– to 5-lobed, (6–) 8–15 × 7–15 cm, margins entire, lobes triangular to ovate, apically acuminate, upper surface dark green, lower surface pale green, softly grey pubescent, particularly along veins; petiole 5–9 cm long, slender, glabrous, exuding milky sap when broken; autumn colour clear yellow. Inflorescence terminal, corymbose, many flowered. Flowers yellowish, 5-merous, usually andromonoecious, sepals elliptic to oblong, ~0.4 cm long, petals oblong to obovate, same length as sepals, stamens 8, inserted in the middle or outside the nectar disc. Samaras 2 to 5 cm long, wings spreading acutely or erect. Flowering in April, fruiting in September (China). (Xu et al. 2008).
Distribution China Chongqing, northern Guangxi, southern Henan, Hunan, western Hubei, Jiangxi, southern Shaanxi.
Habitat Mixed forest in valleys, 300–1650 m asl.
USDA Hardiness Zone 6-7
RHS Hardiness Rating H5
Conservation status Least concern (LC)
Taxonomic note van Gelderen et al. (1994) treated Acer fulvescens as a synonym of the earlier A. longipes, though Xu et al. (2008), whose treatment we follow here, considered them separate species. See below for further context. Xu et al.’s (2008) treatment of A. longipes also contains no lower taxa. Its subspecies as circumscribed by van Gelderen et al. (1994) are treated within A. amplum. See the account of that species for additional information.
Acer longipes has long been confused in cultivation, due to what might be described as over-enthusiastic lumping as well as many a misidentification of cultivated material. Grimshaw & Bayton (2009) joined many in following the treatment of van Gelderen et al. (1994) who reduced A. fulvescens to a synonym of A. longipes, thus the mature, Wilson-derived A. fulvescens in collections all became A. longipes, which in truth is much the rarer of the two species in cultivation. However, van Gelderen et al. (1994) had overlooked a key distinction between the two species, being that the branchlets of A. fulvescens are brown woody by the end of the the first growing season (as in A. pictum) and those of A. longipes remain green (as in A. cappadocicum).
The second round of confusion came with many of the SICH Section Platanoidea introductions also being grown, and written of, as A. longipes in Grimshaw & Bayton (2009), while these in fact belong to quite different taxa, namely A. cappodicum subsp. sinicum and A. pictum subsp. macropterum (details of each are provided in the accounts for those taxa). The illustration on page 89 of New Trees labelled A. longipes subsp. longipes shows a tree that appears not to belong to true Acer longipes, though to which species it does belong is not clear, with careful observation of the branchlets required to determine between A. cappodicum subsp. sinicum and A. pictum subsp. macropterum.
True A. longipes is known in cultivation from only two mature plants, believed to be from two separate collections made by Ernest Wilson (K. Rushforth, pers. comm. 2014). Both are at Arley Castle, Worcestershire, with one found in the garden and the other in the neighbouring Naboth’s Vineyard. Given that they have thus far proved difficult to propagate via grafting (K. Rushforth, pers. comm. 2015), genuine A. longipes remains one of the rarest maples in cultivation. A thus-far unverified specimen grows at Rogow Arboretum, Poland (P. Banaszczak, pers. comm. 2020), though 12 authentic seedlings are currently being nutured at Longwood Gardens, Pensylvania, having been collected in Hubei in 2018, under NACPEC 18–007 (P. Zale, pers. comms. 2020).