Okay, before I got distracted by a kidney stone, I was in the middle of a theme week of Flower Fairies. Here's what was scheduled to be the last of that series:
knapweed (NAP-weed) - n., any composite plant of the genus Centaurea, especially the weedy C. nigra, with purplish thistle-like flowers.
There are between 350 and 600 species, depending on who's doing the counting, and some species are highly invasive. Also called centaury (though there's an unrelated genus also called that), centory, hardheads, starthistles, and sometimes even cornflower (also unrelated to the regular cornflowers). This name first showed up in the early 15th century as knopwed, from knop, alternate form of knob + wed, alternate form of weed.

Oh, please, little children, take note of my name:
To call me a thistle is really a shame:
I’m harmless old Knapweed, who grows on the chalk,
I never will prick you when out for your walk.
Yet I should be sorry, yes, sorry indeed,
To cut your small fingers and cause them to bleed;
So bid me Good Morning when out for your walk,
And mind how you pull at my very tough stalk.
---L.
knapweed (NAP-weed) - n., any composite plant of the genus Centaurea, especially the weedy C. nigra, with purplish thistle-like flowers.
There are between 350 and 600 species, depending on who's doing the counting, and some species are highly invasive. Also called centaury (though there's an unrelated genus also called that), centory, hardheads, starthistles, and sometimes even cornflower (also unrelated to the regular cornflowers). This name first showed up in the early 15th century as knopwed, from knop, alternate form of knob + wed, alternate form of weed.

Oh, please, little children, take note of my name:
To call me a thistle is really a shame:
I’m harmless old Knapweed, who grows on the chalk,
I never will prick you when out for your walk.
Yet I should be sorry, yes, sorry indeed,
To cut your small fingers and cause them to bleed;
So bid me Good Morning when out for your walk,
And mind how you pull at my very tough stalk.
—Cicely Mary Barker
---L.