bluet
noun
blu·et ˈblü-ət 
: any of several perennial North American herbs (genus Hedyotis synonym Houstonia) of the madder family
especially : one (Hedyotis caerulea synonym Houstonia caerulea) having tufted stems and bluish, white, or purplish flowers with yellow centers
Example Sentences
Recent Examples on the Web The remains of an old CCC latrine stand amid a meadow of tiny, violet flowers called bluets. 
Sarah Kaplan, chicagotribune.com, 11 Sep. 2019 There are Johnny-jump-ups and spring beauties and little bluets. David Grann, The New Yorker, 1 Mar. 2017
Sarah Kaplan, chicagotribune.com, 11 Sep. 2019 There are Johnny-jump-ups and spring beauties and little bluets. David Grann, The New Yorker, 1 Mar. 2017 Word History
Etymology
probably from blue entry 1
First Known Use
circa 1821, in the meaning defined above