What is the best bee plant for wet clay soils in zone 4

[StephenL]

I am looking for a good bee plant that will grow in wet, acidic, clay soils in zone 4. Does anybody have any experience with this or suggestions - other than swamp milkweed? Swamp milkweed is supposed to be good, but it is considered toxic to mamals and spreads rapidly. The area around where I want to plant these flowers is used for hay and therefore it would not work to have milkweed spread into the hay field. Thank you for any help.

[RayMarler]

I'm in zone 9 so not a match there, but i've got red clay soil and now it's wet, but the white dutch clover is thriving in it. I've read where some clovers do real well in clay soils and it does do well here in mine.

[robherc]

Buckwheat's a fairly ideal bee forage, useful as livestock feed/forage, and grows well in most soils & climates; I've talked to people who grew it quite successfully in NE Ohio (zone 5B), so I'm guessing it'll likely work for you.

[Spark]

You can use Field Peas