Giant ironweed is a variable species throughout its range, making it a good example of ecotypic variation. Other species with variation confined to different areas of their range are said to have typostrophic variation. This all matters to those who try to figure out if evolution occurs through isolation of the variations, or gradually within a larger population. I wonder if it isn't a facile argument? If a plant acquires an new advantageous gene, I suspect it will increase its numbers whether isolated or included. Sort of like ladies with red hats. Advantagous traits will prevail.