Boraginaceae : Not just sky-blue!
Most - but by no means all - of the plants of Forget-Me-Not family, known in Latin as Boraginaceae after the Mediterranean star-flowered borage, have blue flowers (sometimes lavender or pink-turning-blue), colored by anthocyanins. These natural dyes may change colors from blue to red, depending largely on the acidity inside the plant cells.
The five-petal flowers range in shape from open starlets to elongated bells. Leaves and stems are typically covered by hoarse hair.
Widely popular forget-me-nots (and their robust, nasty look-alikes, stickseeds), bluebells, and heliotropes belong to this family, as do delicate hounds-tongues and weedy stoneseeds.