Musa siamensis or Thai Gold Banana is a quite recent discovery: it was discovered in the east of Thailand in 2002, soon exported to the West and was first described by Häkkinen, M. & R. H. Wallace in “Folia Malaysiana” in 2007.
Häkkinen, M. & R. H. Wallace. 2007. Musa siamensis, a new Musa species (Musaceae) from S.E. Asia. Folia Malaysiana. 8: 61–70. http://www.foliamy.com/content4.htm