Flowers and weeds

Chapter 7 endnote 5, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

A dandelion is often considered a weed, but it transforms into a flower when placed in a bouquet of wildflowers or if it’s a gift from your two-year-old child. [...] Even biologists’ criteria for flowers and weeds are subjective.

Biologists stipulate that flowers and weeds are categories that have certain criteria. Flowers are plants that have blossoms used in reproduction. Weeds are plants that:

1. grow persistently
2. are destructive
3. interfere with the growth of other, more desirable plants (e.g., produce more seeds that are easily transported and established; plants grow faster and become established rapidly so use up resources like water, nutrients, and might shade smaller plants).

Notice that the biologist’s criteria for weediness has more to do with a plant’s functional properties than its biological properties, such as “it interferes with the growth of more desirable plans” and “is unusually persistent in its growth.” But these criteria do not “carve nature at its joints.” Destructive, hardy plants can have blossoms; for example, honeysuckle meets the functional criteria for weediness, but its sweet scent and beautiful blooms make it popular in cultivated gardens. Bamboo, a useful wood, is unusually persistent. (I once had it growing in my backyard. Trust me, it is impossible to kill.) Thistles, also a persistent grower, are often used in upscale flower arrangements here in Boston. Many plants meet the criteria for "weediness" but are not treated as weeds, like Queen Anne’s Lace, dandelions, chicory, garlic, and Jerusalem artichoke. Some are even food. For example, Daucus carota is also called a wild carrot and is the parent plant from which modern day carrots derive.

A version of the flower-weed example was also used by Shweder.