Anax tristis

{{short description|Species of dragonfly}}

{{redirect|Magnificent emperor|the species of Asia and far southeastern Europe|Anax immaculifrons}}

{{Speciesbox

| name = Black emperor

| image = Anax tristis 002176-1b.jpg

| image_caption = Male

| status = LC

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Clausnitzer, V. |author2=Suhling, F. |author3=Dijkstra, K.-D.B. |date=2016 |title=Anax tristis |volume=2016 |page=e.T59814A72314386 |doi=10.2305/IUCN.UK.2016-3.RLTS.T59814A72314386.en |access-date=16 November 2021}}

| taxon = Anax tristis

| authority = Hagen, 1867

| synonyms =

}}

Anax tristis, the black emperor or magnificent emperor, is an African species of dragonfly in the family Aeshnidae. At up to about {{cvt|120|mm}} in total length and {{cvt|135|mm}} in wingspan, it is one of the world's largest dragonflies and the largest in Africa.{{cite web| title=Anax tristis | url=http://defworld.freeoda.com/Species%20Details/Anax%20tristis.html | publisher=defworld | access-date=25 November 2023 }}{{cite web| title=Black Emperor (Anax tristis) | date=18 May 2020 | url=https://thebdi.org/2020/05/18/black-emperor-anax-tristis/ | publisher=Biodiversity & Development Institute | access-date=25 November 2023 }}

This common species has been recorded from much of sub-Saharan Africa, including Angola, Botswana, Cameroon, Chad, Comoros, Ivory Coast, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Kenya, Liberia, Madagascar, Malawi, Mauritania, Mozambique, Namibia, Nigeria, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe, possibly Burundi, and possibly Ethiopia. It has been recorded once as a vagrant in the Maldives and in Oman. It is found at pools, waterholes, dams, marshes and other types of usually small, standing and temporary waters, generally in open habitats such as savannas but sometimes also in forest openings.{{cite web| title=Black Emperor, Anax tristis, Swartkeiser | url=https://www.dragonflies.co.za/odonata-anisoptera/emperors-genus-anax/black-emperor-anax-tristis | publisher=dragonflies.co.za | access-date=25 November 2023 }}{{cite web| title=Anax tristis Hagen, 1867 | url=http://addo.adu.org.za/index.php?taxon_id=41100 | publisher=ADDO – African Dragonflies & Damselflies Online | access-date=25 November 2023 }}