Acer truncatum

{{Short description|Species of maple}}

{{Speciesbox

|image = Acer truncatum Leaf.jpg

|image_caption = Foliage

|status = LC

|status_system = IUCN3.1

|status_ref = {{cite iucn |author= Chen, Y. |author2= Gibbs, D. |author3= Oldfield, S. |date=2018 |title= Acer truncatum |volume=2018 |page= e.T193886A2288883 |doi= 10.2305/IUCN.UK.2018-1.RLTS.T193886A2288883.en |access-date=30 October 2022}}

|genus = Acer

|parent = Acer sect. Platanoidea

|species = truncatum

|authority = Bunge

}}

Acer truncatum, the Shantung maple,{{BSBI 2007 |accessdate=2014-10-17 }} Shandong maple, or purpleblow maple, is a maple native to northern China, in the provinces of Gansu, Hebei, Henan, Jiangsu, Jilin, Liaoning, Inner Mongolia, Shaanxi, Shandong, Shanxi, and to Korea.{{cite web|url=http://efloras.org/florataxon.aspx?flora_id=2&taxon_id=200013134 |title=Acer truncatum |author1=Tingzhi Xu |author2=Yousheng Chen |author3=Piet C. de Jong |author4=Herman John Oterdoom |author5=Chin-Sung Chang |work=Flora of China |publisher=Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA |accessdate=14 May 2015}}

It is a medium-sized deciduous tree growing to {{convert|15|m|ft}} tall with a broad, rounded crown. The bark is smooth on young trees, becoming shallowly ridged with age. The leaves are opposite, palmately lobed with five lobes, {{convert|5|cm|in}} to {{convert|12|cm|in}} long and {{convert|7|cm|in}} to {{convert|11|cm|in}} broad, with a {{convert|3|cm|in}} to {{convert|10|cm|in}} petiole; the lobes are usually entire, but occasionally with a pair of teeth on the largest central lobe, and the margin is often wavy. The petiole bleeds a milky latex when broken. The flowers are in corymbs, yellow-green with five petals {{convert|5|mm|in}} to {{convert|7|mm|in}} long; flowering occurs in early spring. The fruit is a double samara with two winged seeds, the seeds are disc-shaped, slightly flattened, {{convert|13|mm|in}} to {{convert|18|mm|in}} across. The wings are {{convert|2|cm|in}} long, widely spread, approaching a 180° angle. The bark is greenish-grey, smooth in young trees, becoming shallowly grooved in mature. It is drought and heat resistant.{{Cite web |title=Acer truncatum {{!}} Landscape Plants {{!}} Oregon State University |url=https://landscapeplants.oregonstate.edu/plants/acer-truncatum |access-date=2024-03-29 |website=landscapeplants.oregonstate.edu}}

It is closely related to, and often difficult to distinguish from, Acer amplum, Acer cappadocicum, and Acer pictum subsp. mono, which replace it further south and west in China, and in Japan. From Acer cappadocicum it is best distinguished by the shoots which turn brown by their first winter, not remaining green for several years. From Acer mono (syn. A. pictum auct. non Thunb.) it is best distinguished by the larger, thicker (less flattened) seeds. Acer truncatum is very unusual among maples in showing hypogeal germination.Flora of China (draft): [http://flora.huh.harvard.edu/china/mss/volume11/Aceraceae-AGH_finishing.htm Acer truncatum]{{dead link|date=October 2016 |bot=InternetArchiveBot |fix-attempted=yes }}