Subsp. macropterum has three- to five-lobed leaves with truncate bases that are pubescent or not beneath. The samaras are 3–4 cm long with wings spreading horizontally. Xu et al. 2008.
RHS Hardiness Rating: H4
The identity of representatives of subsp. macropterum have been somewhat confused in collections. It is known in cultivation from two collections, SICH 1814, collected in Nanjiang County, Sichuan in 1996 and SICH 2087, also collected in Nanjiang County, in 1999. Both have been found in collections under names A. cappadocicum subsp. sinicum and A. longipes. The former grows well at Wakehurst, West Sussex and Westonbirt Arboretum, Gloucestershire, where it has made an attactive tree with a rounded crown. Interesting variation has been found within seedlings of SICH 2087, with some, though far from all specimens, taking a fastigiate form. Examples grow at Hergest Croft, Herefordshire and RBG Kew. In both examples, red developing fruits contrast very satisfactorily with the green foliage.
Similar in leaf form to Acer truncatum, A. pictum subsp. macropterum can be distinguished from that species in its fruits with wings more than twice as long as the nutlet. A collection of A. pictum from Seo My Ty, northern Vietnam, made by Dan Hinkley in 2006 appears, in leaf and flower, closest to this subspecies. This collection represents an extension of the range of A. pictum, not previously recorded from Vietnam, though the habitat in which this collection was made has since been destroyed. Though recorded as A. pictum subsp. macropterum in Grimshaw and Bayton (2009), SICH 1107 belongs to A. cappadocicum subsp. sinicum rather than to this taxon.