The website https://www.minnesotawildflowers.info/ is a great resource for learning about Minnesota native plants; you can find flowers by bloom date or color, for example, and lots of great photos.
From the website:
Our mission is to educate Minnesotans on our native plants, raise awareness on threats like invasive species, and inspire people to explore our great state, appreciate its natural heritage, and become involved in preserving it.
Over 1,300 plant species and more than 11,000 high quality photos are cataloged here, with more added each week, working towards recording all 2100+ plant species in Minnesota.
Help support this wonderful resource by contributing now to their fundraising campaign – at press time they were half way to their $10,000 goal.