I'll keep my eye out.
At least three of those are found in my region but we have had such dry times that populations of mints have declined.
In some parts of Australia recent rains have been good, some rivers have had good flows, unfortunately not yet those in my region.
Finding Mentha seed is no easy task. One first needs to locate a site which has been well watered(not common). Then one needs to sit and wait until the mint does set seed(again uncommon). Then comes the even tricker parts, collecting and germinating.
In Australia you really often have to be right on the ball at the correct time and place to get good seed of many of our plants.
Mentha seed may require very long germination periods though germination is relatively rapid if the conditions required are met. However growing from seed isn't very reliable. What must be realised is that in Australia many of the Mentha species from other parts of the world now exist here and many are feral. Seed may easily be hybridised. From this point of view it would probably be wiser to come and study these mints .. in Australia.
further discussion here.. http://www.bushfood.net/viewtopic.php?t=315
http://www.ibiblio.org/pfaf/cgi-bin/arr ... +australis
http://www.dpiw.tas.gov.au/inter.nsf/At ... tralis.pdf
_ Any plant will grow from a single bud if you can replicate the required circumstances.