Quercus longinux

{{Short description|Species of oak tree}}

{{Speciesbox

| image = Quercus Longinux.jpg

| genus = Quercus

| display_parents = 2

| parent = Quercus sect. Cyclobalanopsis

| species = longinux

| authority = Hayata

| synonyms_ref = [http://www.theplantlist.org/tpl1.1/record/kew-173687 The Plant List, Quercus lobbii Ettingsh. ]

| synonyms = {{collapsible list|bullets = true

|Cyclobalanopsis kanehirae Nakai

|Cyclobalanopsis longinux (Hayata) Schottky

|Cyclobalanopsis pseudomyrsinifolia (Hayata) Schottky

|Cyclobalanopsis taichuensis (Hayata) Schottky

|Quercus glauca var. longinux (Hayata) Menitsky

|Quercus glauca subsp. longinux (Hayata) Menitsky

|Quercus kanehirai Nakai

|Quercus pseudomyrsinifolia Hayata

|Quercus taichuensis Hayata

}}

}}

Quercus longinux is an uncommon Asian species of trees in the beech family Fagaceae. It has only been found in Taiwan.[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=210000387 Flora of China, Cyclobalanopsis longinux (Hayata) Schottky, 1912. 长果青冈 chang guo qing gang ] It is placed in subgenus Cerris, section Cyclobalanopsis.{{Cite journal |last1=Denk |first1=Thomas |last2=Grimm |first2=Guido W. |last3=Manos |first3=Paul S. |last4=Deng |first4=Min |last5=Hipp |first5=Andrew L. |date=2017 |title=Appendix 2.1: An updated infrageneric classification of the oaks |website=figshare |doi=10.6084/m9.figshare.5547622.v1 |url=https://figshare.com/articles/dataset/Appendix_2_1_________An_updated_infrageneric_classification_of_the_oaks/5547622/1 |access-date=2023-02-24 |format=xls |name-list-style=amp }}

Quercus longinux is a tree. Leaves can be as much as 8 cm long. Acorn is up to 12 mm long, narrower than those of most other species in the subgenus.[https://www.biodiversitylibrary.org/page/39205738#page/308/mode/1up Hayata Bunzô 1911. Journal of the College of Science, Imperial University of Tokyo 30(1): 292–293] description in Latin, commentary in English