This is my husband’s favorite driveway-crack flower because it is truly blue. Blue wildflowers usually lean toward violet or lavender or purple, but not this thing.
We’re talking Giotto fresco blue. Or Crayola crayon blue.
Asiatic dayflower, Commelina communis.
Several species of dayflowers and spiderworts commingle in Nashville, but this one and the lookalike C. erecta may be the most abundant. Communis means communal, or colony-forming, which this is; and also means common, which this is.
Dayflower means a day of flower. One day and pffft: gone to seed.
It’s everywhere in suburbia, but the blooms are small. They look like two blue mouse ears, but there’s a third petal, too: tiny, white and hidden. There’s a story behind those three petals, which I’ll get to below.
Asiatic dayflower likes shady. It seeds itself in our driveway, in the north shade of the porch, and inside most flower pots. In the neighborhood we see it in shady edges of “real ” yards (lawns not poisoned with weed ‘n’ feed), beside shrubs, and along the secret sidewalk the city forgets to maintain.
The flowers make pretty garnish on salads, and the young leaves are edible, but they taste like grass to me.
SPOT THE DIFFERENCE
Asiatic dayflower (C. communis) and our native Slender dayflower (C. erecta) are lookalikes. The quickest way to spot difference is by a spot: the non-native has a dark little spot in the yellow part of the flower (“yellow antherodes with maroon centers.” The native has yellow with no spots.
Other differences: the non-native one develops white roots at every node (and is thus not “erecta.”) And, the Asiatic one has its flower tucked inside a green taco open from end to end. The native taco is shut at one end (looks fused, but isn’t). The real name for the taco is spathe.
Leaves differ, too: our native tends to have narrower leaves.
THE STORY OF THE THREE PETALS
As I mentioned, the flower face has two blue petals and a smaller white one. And, as I mentioned, there’s a story there. Actually, there is more than one version of the story and I’m not certain which is true. I do know which one is the most colorful to recite on wildflower hikes.
Linnaeus—the guy who standardized binomial (two-name) classification—supposedly named the genus Commelina after three Dutch brothers, surname Commelin. Two brothers accomplished great things (thus the two big blue petals), and one brother either 1) died young or 2) was a lazy jerk or 3) both (thus the one tiny white petal).
Linnaeus says in Critica botanica:
“Commelina has flowers with three petals, two of which are showy, while the third is not conspicuous; from the two botanists called Commelin, for the third died before accomplishing anything in botany.”
But other sources indicate the Commelins were not brothers, but botanist Jan; Jan’s botanist nephew Caspar; and Caspar’s physician son, Caspar Jr.
And one source (at least) says Plumier named the genus. As Plumier died when lil’ Caspar Jr. was four, there’s no way the third Commelin was the puny petal.
But, “three brothers” and “died young” make good copy. As does the lazy slacker version below:
Vick’s Illustrated Monthly Magazine 1899, Volume 23
Three brothers, “two were useful and productive citizens, while the other was not highly esteemed by Linnaeus for the great father of modern botany has taken a subtle but unmistaken way of expressing his disapproval of the third brother. The plant that is named after the three brothers has three petals, two of which are plump and fair to see, being a delicate light blue, while the third petal is barely seen at the first glance, being smaller, and white or colorless. This colourless little petal is supposed to represent the brother whom Linnaeus held in disdain.”
Other plants in the Driveway-Crack series:
Driveway-Crack Flowers: White Clover
Driveway-Crack Flowers: Perilla
Driveway-Crack Flowers: Venus’s Looking Glass
Driveway-Crack Flowers: Evening Primrose
More
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