Carex tristachya
{{Short description|Species of flowering plant}}
{{Speciesbox
|image=Carex tristachya megsg02.jpg
|image_caption=Inflorescence, showing the three female spikelets
|genus=Carex
|species=tristachya
|authority=Thunb.J.A.Murray, Syst. Veg. ed. 14: 845 (1784)
|synonyms=
- Carex pocilliformis Boott
- Carex tristachya subsp. pocilliformis (Boott) T.Koyama
}}
Carex tristachya, called the shiny-spike sedge, is a species of flowering plant in the genus Carex, native to south-central and southeast China (including Hainan and Taiwan), Korea, Japan, the Ryukyus, the Philippines, Borneo, and New Guinea.{{cite web |url=http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:927467-1 |title=Carex tristachya Thunb. |author= |date=2017 |website=Plants of the World Online |publisher=Board of Trustees of the Royal Botanic Gardens, Kew |access-date=31 January 2021 }}{{cite book |author-link= |date=August 2015 |title=한반도 자생식물 영어이름 목록집: English Names for Korean Native Plants |url= |location= |publisher= 국립수목원|page= |author1=국립수목원 |isbn=9788997450985 }} Its seeds are dispersed by ants.{{cite journal |title=Interference competition among disperser ants affects their preference for seeds of an ant-dispersed sedge Carex tristachya (Cyperaceae) |year=2016 |last1=Tanaka |first1=Koki |last2=Suzuki |first2=Nobuhiko |journal=Plant Species Biology |volume=31 |pages=11–18 |doi=10.1111/1442-1984.12073 }}