Quercus furuhjelmi

{{Short description|Species of oak tree}}

{{More citations needed|date=May 2018}}

{{Speciesbox

|fossil_range = {{fossil range|Paleogene}}

|extinct = yes

|image =

|genus = Quercus

|species = furuhjelmi

|authority = Heer

}}

Quercus furuhjelmi was a type of 'brown (or chestnut) oak' that lived in the Paleogene period. It is only known by its fossil remains, which have been found in Kazakhstan and Alaska.{{cite journal |url=https://doi.pangaea.de/10.1594/PANGAEA.526586 |author1=Bruch, Angela A |author2=Zhilin, Sergey G |year=2006 |title=Miocene macroflora of Ashutas (Kazakhstan) |website=PANGAEA |doi=10.1594/PANGAEA.526586 |access-date=20 May 2018}}{{cite web |url=https://www.researchgate.net/publication/260135711 |title=Palynology of Eocene strata in the Sagavanirktok and Canning Formations on the North Slope of Alaska |website=Palynology 26(1) |volume= |pages=59–93 |date=December 2002 |author= |access-date=20 May 2018}}

According to some authorities (Trelease, 1924), they were related to the white oaks, subgenus Lepidobalanus (or Leucobalanus) while others relate them to the Heterobalanus of East Asia.

Chestnut oaks are a seemingly polyphyletic group. The chestnut oaks of East Asia (for example Q. crispula Blume) have been placed in the subgenus Heterobalanus, while a chestnut oak from western North America{{Snd}}Q. sadleriana R.Br.ter{{Snd}}is considered by some to be a member of the Leucobalanus subgenus and by others to be in the Heterobalanus subgenus.

Comparison of the brown leaves of the chestnut tree and the brown oaks does not indicate any fundamental distinction between the foliage of these groups, although some species of heterobalanus have some pointed teeth, which are absent in Leucobalanus. Some specimens of Q. furuhjelmi also had some sharp teeth, which suggests that this species was probably related to Heterobalanus.{{cite web |url=https://www.fs.fed.us/psw/publications/documents/psw_gtr044/psw_gtr044_001.pdf |author= |title=Ecological Relationships: Neogene History of the California Oaks |quote="Several specimens of the early and middle Miocene Alaskan Q. furuhjelmi Heer are definitely bristle-tipped (Wolfe and Tanai)" |date= |website=fs.fed.us |access-date=21 May 2018}}{{cite book |url=https://books.google.com/books?id=B_PEFR9iJR4C&dq=fossil+Quercus+furuhjelmi&pg=RA5-PA32 |title=U.S. Geological Survey Professional Paper, Issues 1101-1108 |year=1980 |via=books.google.co.uk |page=32 |access-date=20 May 2018}}