I'm pretty sure Deb is right that #3 is sweet clover. Sometimes white sweet clover is lumped in with M. officinalis
, other times it's considered separate and called M. albus
or M. alba
. Here are some good pictures
of M. albus
if it helps you make a positive ID. The University of Michigan Herbarium says that it's an Old World species that is widely cultivated as a forage plant. It is attractive to bees and is "characteristic of recently disturbed places in dry, open, often calcareous ground, such as sand dunes, prairies, and roadsides, as well as fields, railroads, and shores".
MSU lists it as an invasive species in Michigan
I think that #4 looks a lot like Lespedeza
of some sort, actually. If you look up L. procumbens
or L. repens
(trailing lespedeza and creeping bush clover), you'll see how the leaves are really similar. Lespedeza species seem to hybridize a lot too, so that plant might not fit neatly into one species or another. Is that plant creeping on the ground? I can't really tell from the picture but it kind of looks like it is.
I don't really know about #2. I think I've seen it here in Michigan before, but it doesn't look like any of the Lespedeza
species that the University of Michigan lists as being present in the state except maybe L. cuneata
. #1 has me totally stumped.
EDIT: The more I look at it, the more I think #2 is L. cuneata