Violets are beautiful spring-blooming flowers that can often be found growing wild in lawns and fields. But have you ever wondered how these pretty little flowers are able to spread their seeds and propagate? Violets have developed some clever evolutionary tricks to ensure their seeds get dispersed far and wide.
Violet Seed Structure
Violet seeds form inside green seed pods that hang down close to the ground after the flower has been pollinated Inside each plump violet seed pod are around 20-50 tiny brown seeds,
The seeds have a special feature – they each have a tiny attachment called an elaiosome The elaiosome is a type of oil-rich appendage that contains fatty acids, amino acids and sugars This nutrient-packed treat on each violet seed plays an important role in seed dispersal, as we’ll see.
Ants Disperse Violet Seeds
Ants are one of the main agents of dispersal for violet seeds. The ants are attracted to the elaiosomes attached to the seeds. When the seed pods split open, ants will carry the seeds back to their nests and feed the nutritious elaiosomes to their larvae.
But the ants don’t actually eat or damage the seed itself. After feeding off the elaiosome, the ants will discard the seed intact. This results in the seeds ending up in the ants’ waste piles, safely away from the original parent plant.
Studies have shown that ants can move violet seeds up to 180 feet away – much farther than if the seeds had just dropped passively!
Other Dispersal Methods
Ants are the main method of dispersal, but violets have some backup plans too. If ants don’t find the seeds, the pods will eventually burst and scatter seeds up to several feet away. This is better than just dropping straight down at the base of the parent plant.
Slug slime trails have also been observed as a dispersal agent. Slugs will eat the elaiosome and leave the seed behind alive to germinate.
Finally, some seeds manage to get swept away by wind or water. However, the majority – up to 90% – get picked up by ants or slugs if given the chance.
Why Dispersal Matters
Seed dispersal is extremely important for plants like violets for several reasons:
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It reduces competition between offspring and parent plants for sunlight, water, and nutrients.
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It allows plants to colonize new areas and spread geographically.
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It reduces predation by spacing seeds away from parental plants.
So while the violet’s seductive seeds seem cleverly designed to appeal to ants, the interaction benefits both species. The ants get a nutritious meal for their larvae, and the violets get their seeds safely transported away from the parent. This fascinating partnership is just one of many ingenious methods plants have evolved for spreading their seeds far and wide.
How Violets Reproduce
Violets reproduce both sexually, through cross pollination of the showy flowers we’re familiar with, and asexually, by self-seeding of less noticeable flowers that remain hidden near the base of the plant.
The roots of this flower are shallow rhizomes, which are thick and spread horizontally. This allows another means for the flower to reproduce, as it can form a large grouping if left unchecked from competition or herbicides.
Propagating Violets
Violets can be propagated by seed or division. The seeds of wild violets are thrown from the plant when mature. This can be a difficult seed to germinate, so it is best to let mother nature do it for you. Just scatter seeds in the general area you wish to grow them, then watch for heart shaped leaves to emerge in spring/summer.
Wild Violet Prevention
These pretty little perennials freely self-seed (they don’t need to bloom to reproduce) and can quickly take over a lawn. To prevent wild violets from spreading, remove the flowers before they go to seed and dig up unwanted plants, being sure to remove all the root pieces.
Flowering and Seed Dispersal
Many violet species, including the common wild violet, have two kinds of flowers. The first, normal flowers are the pretty ones we see in the spring. The second type of flower is hidden, staying closed near the base of the plant. These closed flowers self-pollinate and produce seeds, allowing violets to spread quickly.
Most violet species have ballistic seed dispersal, meaning that seeds can be dispersed up to 5 meters away from the mother plant. As the seed capsule dries, the seeds are pinched and then they fling out. This explosive dispersal, combined with ant dispersal, allows violets to propagate efficiently in nature.
What to Look For:
Dragon jaws. Tiny, three-jawed capsules lined with teeth violet seeds. There are hundreds underfoot in my yard right this minute.
Also, look nearby for what will be the next dragon jaw: a rather boring pod in white, green, or black. Three “closed” flowers: one ready to shoot, and two in waiting
But the pod isn’t really a pod: it’s a FLOWER: a secret flower. Yard violets make two sorts of flowers: 1) the open, purple/blue kind with petals, and 2) the closed kind, with no petals.
The dragon jaws are the closed flowers after they burst open.
“Cleistogamous” describes the closed flowers, and it means “closed marriage.” No need for pretty petals or colors to lure insects: these flowers pollinate themselves, in private.
Here’s the ballistic part: when the jaws open, they dry out, bit by bit, and release the teeth (seeds) via “ballistic dispersal.” Mechanical ejection! They shoot! But because the flower stems are usually down low, sometimes at the soil line, seeds can fall back around the mama plant, which can explain why so many babies encircle mama in spring.
Violets use another bold move in reproduction: bait.
Each seed is equipped with a tiny treat: a blip of fatty goodness to lure ants.
Ants carry the seeds home, feed the fatty blip to the larvae, and then toss the seed in the trash. This dispersal method ensures distance from the mama plant, and can spread violets farther than the low shots that fall nearby. Plus, ant trash tends to be a fertile place for seeds to sprout.
I’ve known this for ages, but never tried to SEE the treat on a violet seed. This time, I took a hand lens to the kitchen table and tried . . . and tried. . . with fresh seeds and older seeds, white and black. Viola sororia seeds
Different violet species have different sizes of treats. (The real term is “eliaiosome”, but let’s say “treat.”) The treats are attached near where the seed was attached. Otherwise, an ant could straddle the open dragon jaw and graze the seeds without taking them anywhere.
My Viola sororia treats must be a sad disappointment to local ants. The only package I see is a wispy wing. That’s it. Everything else is seed-coat.
But in pictures of the English violet (the original “shrinking” violet), the treat is obvious. It’s plump! It’s alluring! If I were an ant, I’d snag it and run.
– Are our homegrown violets guilty of false advertising? – Do they promise sirloins, but deliver Saltines? – Are they like that house at Halloween who hands out candy corn instead of Reese Cups??
I’ve read that Viola species can differ greatly in size of treat and in amount of ballistic force. With some, ant dispersal (via big treats) is the primary method. In others, mechanical ejection.
So far, I’ve not seen a single ant interested in my dragon jaws, so I’m guessing our yard violets specialize in ballistics. And as I said above, this could explain why so many seeds end up germinating right beside Mom. Which would mean that our common violets excel at tricks, not treats.
Viola sororia: free, native groundcover; lawn diversifier; butterfly host-plant. Never needs mowing.
Cleistogamous: closed flower that relies on self-pollination.
Chasmogomous: open flower that usually relies on cross-pollination.
Myrmechochory: dispersed by ants.
Elaiosome: the blip of tasty fat on a seed, which entices ants to tote it home for Junior.
Watch violets go ballistic in slo-mo in this Smithsonian video: (the first 30 seconds)
-Here’s a beautiful post at the Natural Web by Mary Anne Borge on some of our most charismatic woodland flowers and their common denominator of elaiosomes: https://the-natural-web.org/2014/05/03/a-carpet-of-spring-beauty-woven-by-ants/
-Awkward Botany has this great page on the chubby elaisomes of the English / Sweet violet, Viola odorata: The Hidden Flowers of Viola.
-Common blue violet as a butterfly host plant? See this page at the Xerces Society. Violets have a specialist mining bee, too!
-More about Viola sororia reproduction, here.
-Study: “Relative importance of ballistic and ant dispersal in two diplochorous Viola species (Violaceae),” here.
-The three-jawed Snaptrapper, from “How to Train Your Dragon.” (#uselessknowledge)
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Bio: Joanna Brichetto is a naturalist and writer in Nashville, the hackberry-tree capital of the world. She writes about everyday marvels amid everyday habitat loss, and her essays have appeared in Creative Nonfiction, Brevity, Fourth Genre, Hippocampus, The Hopper, Flyway, The Common, Stonecrop Review, The Fourth River and other journals.
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FAQ
How do violets disperse their seeds?
Each seed is equipped with a tiny treat: a blip of fatty goodness to lure ants. Ants carry the seeds home, feed the fatty blip to the larvae, and then toss the seed in the trash. This dispersal method ensures distance from the mama plant, and can spread violets farther than the low shots that fall nearby.
How do violets spread seeds?
Wild violets are native to Minnesota. They spread vigorously by seed and rhizome. Seeds explode off small green fruits and are often carried away by ants to feed their larvae.
Do violets reseed themselves?
Wild Violet Prevention
These pretty little perennials freely self-seed (they don’t need to bloom to reproduce) and can quickly take over a lawn.
How do wild violets spread?
Wild violet plants also spread through underground rhizomes. Growing violets is easy and with care they have many uses in the garden. Wild violets make great accents around trees, near water sources, and beds. They also make excellent choices for instant ground cover in a woodland garden. They can even be grown in containers.
Do violets eat seeds?
However, the animals do not digest the seeds, which are able to germinate many meters away from the parent plant. Many plants are dependent on outside help to ensure that their offspring flourish. Violets enlist the aid of ants and slugs to carry away their seeds and release them where they can grow.
How do violets grow in Indiana?
Violets spread by short rhizomes and by seed. Short rhizomes about the size of your “pinky” finger are common to all Indiana wild violet species. Wild violets are typically found in shady areas with moist soil but they can also grow in sunny, droughty areas. Wild violet rhizome on soil surface.
Can a hose propagate wild violets?
hose choosing to propagate wild violets can divide established plants in spring or fall, though their self-seeding capabilities make this unnecessary. Seeds can also be collected and then sown in fall either indoors or in a cold frame.
Do violets eat ants?
Like trilliums and trout lily (Erythronium americanum), violets also use seed dispersal by ants, a process known as myrmecochory. Their seeds have elaiosomes attached to them which are fatty deposits attractive to ants. The ant finds a seed, eats the nutritious coating then buries it. No wonder violets do so well in landscapes.
Do wild violets self-seed?
Keep reading to learn more about wild violets care. Wild violets (Viola odorata) have heart-shaped leaves with purple-blue flowers. Some varieties also have white or yellow blooms. Although in some areas they are considered annuals or biennials, wild violets often self-seed, coming back each year in unexpected locations.