Regarded by some to be just another common weed yet meriting an old and enduring rhym
No heart can think, no tongue can tell,
The virtues of the pimpernell.
This species used to be highly valued as a medicinal plant but the saponins apparently make it toxic enough to be a potentially fatal choice of self-medication. I’ve been told by more than one herbalist that it fell out of use more than a century ago but I have not yet found actual details about when or why or how.
I would not suggest ingesting the plant but should comment that it has a strong weirdly prickly feeling taste.
While still in college, I read someplace, perhaps in Milspaugh’s work from the 1800s on medicinal plants, that the name anagallis meant inducing laughter.
Ingestion of the green plant material was said to cause a mild feeling in the chest and throat that purportedly resembled the onset of laughter. I might disagree with the latter analogy but it did produce a strange sensation in my upper chest when I tried it circa 1981. It was not unpleasant but, unlike laughter, there not much desire to repeat the experience.
Color reproduction of the flower color is inexplicably poor in these images. The flower on the upper left in the image above is, of those on this page, perhaps among the closest to being true.
Those purple spots under the leaves make this one easy to identify with certainty.