Last summer, while I was enjoying the ubiquitous glories of the vast stands of fireweed stretching from the Canadian border to the heart of Alaska, I noticed something unusual. Almost always, with a stand of fireweed, were a few stems of yarrow, a white, sometimes pink flower, shaped like a flattened umbrella, with stalks of feathery leaves. Except for a stand of pink ones, whose twilit luminosity attracted me, I almost never took pictures of it, and, after weeks of this, began to be intrigued, not so much by the yarrow, but by my lack of interest in it. I take pictures of every flower I come across, why not yarrow?

Even the fireweed is having a hard time competing with the coastal slopes of Valdez, Alaska, but the yarrow is almost invisible. You can find one in the left lower corner, and then follow a slight curve up and right for three more

Ever since we started naming them, we’ve tended to pay a lot of attention to the more beautiful, fiery goddesses, and it’s easy to see fireweed — lush, fertile, gorgeous — as the queen of her surroundings, Aphrodite cloaked in magenta. Yarrow, by contrast, is almost invisible with such a companion. Even without fireweed around, yarrow is a quiet and unassuming plant, not, to my eyes, particularly pretty, and not photogenic. Flattish circles of tiny individual flowers are hard for the camera to do justice to, and yarrow, with its lack of contrasting color and texture, is particularly challenging.

A quiet presence in a meadow in the Kenai Wildlife Refuge, Kenai, Alaska

Having ignored yarrow for most of my trip north, it then kept tugging at me once I got back to California. Its official name is Achillea. Why, I wondered, did Carl Linnaeus, the eighteenth-century father of botanical nomenclature, name quiet yarrow after an ancient Greek hero, known as much for rage as courage? Legend has it that Achilles used yarrow to staunch the blood of his wounded enemy-then-ally, Telephus, though yarrow itself is never mentioned in the Iliad.   But it was enough for Linnaeus, and, since yarrow leaves have traditionally been applied to the skin to stop bleeding, it’s one of the plants he could have used.

Among fireweed leaves on a twilight walk along the road in Moose Pass, Alaska

We know it was used many millennia before theTrojan War, in twelfth century BCE, because 50,000-year-old yarrow grains have been found in the tartar of Neanderthal teeth. Since yarrow has known medicinal properties but is not known for significant nutritional value, researchers concluded that the Neanderthals were up on their available medications. Native Americans had many uses for yarrow, including steeping the leaves for a tea to lower fever, help with sleep, and settle the stomach. Its ability to heighten the effects of alcohol apparently prompted the Vikings to use it in beer specially brewed to be drunk at weddings, which gives a hair-raising slant on Viking nuptials.

A close look at the two flowers that make up the aster family: a central disk flower and the surrounding ray flowers, looking like petals

The whole northern hemisphere could have benefited from the use of yarrow, and most likely did, since it’s native virtually everywhere north of the equator, and is a pharmacopeia in itself. Its very usefulness would have helped its spread, as travelers carried it with them. A member of the vast Asteraceae family, the flowers are formed by its family’s signature two structures — a disk floret in the center, surrounded by ray florets, looking like petals. Each quarter inch yarrow flower is clustered with many others to form a head, which branches out from a stiffly erect, rather brittle stalk covered with delicate, finely cut leaves.

The yarrow in Alaska is Achillea millefolium, variety borealis.

All achilleas share these traits, but there are genetic variations that have allowed them to adapt to higher and lower altitudes, dryer and wetter climates, differences in available light and nutrients. Yarrow’s adaptability is helped by its intriguing genetic promiscuity. Unlike animal genes, where offspring get a pair of chromosomes, one from each parent, plants can have multiple copies of their chromosomes, a state called polyploidy. Those with four copies are tetraploids, six are hexaploids, eight are octoploids.

Animals would not mate across such a variation, but plants, and especially yarrow, do, complicating the effort to sort them into species. Experts have, at different times, classified Achillea millefolium as 40 different species, and then changed their collective minds and lumped all variations into one, retreating into the umbrella term ‘species complex.’ So most likely all the yarrow I’ve seen in my life, including the cultivars for gardens, are versions of Achillea millefolium, the second name referencing its ‘thousand leaves,’ with ‘borealis’ added as I got farther north.

My growing interest in a plant I spent the summer overlooking reminds me of a moving interview with the actor Dustin Hoffman on his role as Dorothy Michaels in ‘Tootsie.’ Before committing to the movie, he wanted to be sure that he could really pass as a woman, so he went to the make-up people at Columbia Pictures to see if that was possible. Once they had done their magic, he said, ‘Great, now make me beautiful,’ and was dumbfounded when they said that was the best they could do. He went home in tears at his own blindness and was in tears recounting the story. He said he thought of himself, in that guise, as an interesting woman, but he realized that if he were to meet her at a party, he would have ignored her in preference for someone more conventionally showy, the fireweed in the crowd.

Knowing that yarrow is a determined and talented plant, adaptable to every circumstance except standing water or extreme desert, or that the leaves are full of minerals for browsers, or that my ancestors used it to lower their fevers, relieve stomach cramps, and kill bacteria in their cuts doesn’t make it any prettier than I found it last summer, but it makes that facile judgment seem silly. It changes the way it looks to me, because my experience of it is richer, layered, connecting me to its energies in a way that relying on its surface charms had not. It brings me into the long history we humans have shared with it, and then further and further back into the tens of millions of years it bloomed on this planet before beings like me were here to be aware of it. Eons of blowing in the wind, soaking up the rain, creating a banquet of food and medicine from the sunlight falling on its leaves and the minerals seeping into its roots. This is how we release all bias. Knowledge is not only power, it’s love.