HERE a little bit of info and the spreading area.
The meaning of the term "Walking Iris" is for many people not clear. HERE you can see this explained in pictures.
The only site with much information about Brasilian plants and especially Neomaricas certified by a university has been created by Mauro Peixoto. The link to that site is HERE .
At the site of the French Iris-Society - HERE - there is an article in French by Maurice Boussard about the genus Neomarica.
And HERE is an authorized German translation by Hannelore Goos.
Also at the site of the French Iris-Society there is an essay by Prof. L. Capellari Jr. (University
of Sao Paulo) available - HERE -
It was translated into French by Boussard and deals with the Iridaceae of Brasil generally, but Neomaricas take a big part of it. The text is illustrated with beautiful pictures.