While you wait for the puddles to drain and the clouds to part, you might want to check out a superb new on-line resource offered by our friends at the University of Michigan Herbarium: Michigan Flora.
Michigan Flora has been the life work Ed Voss. For those who know Dr Voss from his classes (this writer studied Boreal Flora under him at the U-M Biological Station) or from his books, it's hard to believe that it's been almost 40 years since the first volume was published, and seven years since the third and last. Since the first volume came out, 42,000 Michigan specimens have been added to the University's herbarium collection, 250 additional species have been recognized (80% of them alien), and numerous changes have been made to the taxonomy and nomenclature.
http://michiganflora.net brings it all up-to-date and on-line. Available are keys to plant families, genera, and species (admittedly difficult to use, but doable with some practice and familiarity). In addition, the goal is to include images of all the species, and a good deal of headway has already been made, as the herbarium staff has been able to access the large slide collection of the late Herb Wagner. Tony Reznicek (whose name has appeared earlier in this blog) is taking the lead in the on-line project.
Just to test it out, I searched the genus Cardamine (the cresses). Well look-ee there! The common cut-leaved toothwort is no longer Dentaria laciniata, but instead Cardamine concatenata. And there's that horrible Cardamine hirsuta, a smallish weed with explosive seed pods that is everywhere in my lawn and garden. Michigan Flora calls it hoary bitter cress. I call it 'poppers.'
Wait a sec! Check out Cardamine impatiens. It's a weed known from only three Michigan counties (one being Washtenaw), and I do believe that it is the newest invasive on my property. I was on my hands and knees pulling it out just a few days, wondering why it keeps re-appearing despite my effort to eradicate it.
Anyways . . . know ye that Michigan Flora is on-line and at your service!