Ponkan (Chinese: 椪柑; Citrus poonensis; "Chinese Honey Orange") is a high-yield sweet Citrus cultivar with large fruits in the size of an orange. It is a citrus hybrid (mandarin × pumelo), though it was once thought to be a pure mandarin.
The fruit is very sweet, round in shape and about 7–8 cm wide in size. Trees are heavy bearing every other year, and sometimes the limbs break due to the heavy yields. Growers resort to propping the limbs up with sticks at times, though if the limb bends gradually down and grows in that position it will do better in future years.
Trees can be propagated by seed, as they breed true, or grafted onto other rootstocks, trifoliate orange being the most popular. Andrew Willis of Apopka, Florida, promoted the Ponkan heavily in the early 1900s.
Ponkans are widely grown in Japan.
|2006 Citrus cultivation in Japan. 
It was originally introduced to the United States by Carlo Roman in 1880. His original grove is still in production, and under the care of Marion Holder near Hawthorne in Putnam County, Florida. The fruit is still very popular in the Melrose area, and often sold at roadside stands there. The city of Teresópolis in Brazil holds an annual Ponkan festival.
- Velasco, Riccardo; Licciardello, Concetta (2014-01-01). "A genealogy of the citrus family". Nature Biotechnology 32 (7). doi:10.1038/nbt.2954.
- Wu, G. Albert; Prochnik, Simon; Jenkins, Jerry; Salse, Jerome; Hellsten, Uffe; Murat, Florent; Perrier, Xavier; Ruiz, Manuel; Scalabrin, Simone (2014-07-01). "Sequencing of diverse mandarin, pummelo and orange genomes reveals complex history of admixture during citrus domestication". Nature Biotechnology 32 (7): 656–662. doi:10.1038/nbt.2906. ISSN 1087-0156. PMC 4113729. PMID 24908277.
- Barkley, Noelle A.; Roose, Mikeal L.; Krueger, Robert R.; Federici, Claire T. (2006-04-20). "Assessing genetic diversity and population structure in a citrus germplasm collection utilizing simple sequence repeat markers (SSRs)". Theoretical and Applied Genetics 112 (8): 1519–1531. doi:10.1007/s00122-006-0255-9. ISSN 0040-5752.
- "Mandarin Orange". purdue.edu.
- "2006 The area under cultivation of Mikan" (in Japanese). National Institute of Fruit Tree Science.
- "2006 The area under cultivation of Citrus (except for Mikan)" (in Japanese). National Institute of Fruit Tree Science.
- Festa da Ponkan, Teresópolis (Portuguese)