The Life and Times of Spring Ephemerals
Our native spring ephemerals live such fascinating lives. Our awareness of their presence is so fleeting -- many of them will flower, go to seed, and die back all in a matter of a couple weeks -- yet many of them are long-lived and have complex ecological relationships. Certainly these small wonders are worth a closer look.
Micranthes virginiensis or early small-flowered saxifrage, is one of the earliest flowering spring ephemerals, though you’re not likely to notice it. It’s basal rosette persists all year long, turning a dark red in the winter and greening back up as the weather warms up. It begins forming buds in the fall, which over winter and open up early in the spring, still low to the ground nestled in the basal rosette, relatively protected from late frosts. Click on the photos for higher resolution versions.
In this photo at the nursery, you can see the flowers just beginning to open. In the wild, it may still be covered by leaf litter, or even snow.
Within a matter of days, the peduncle will rocket upwards to six or more inches, creating a tall broad panicle of flowers.
This is the same plant as above, taken just 4 days later.
This saxifrage favors rocky soils, and often are found growing in crevices, outcroppings, or other nooks and crannies in moist to dry forests across northern Virginia.
A close up of freshly opened flowers. Notice that not all the anthers have begun to form pollen.
Supposedly, the tall, densely hairy stems are meant to discourage ants from visiting flowers, in favor of flies and bees which pollinate more efficiently. (1)
Speaking of ants, we can see here an ant visiting visiting a Cardamine concatenata or cutleaf toothwort. Toothwort also has a hairy stem, though in this case it did nothing to deter the presence of the ants, if in fact that is what the plant “intended.”
This was just one of about a dozen ants visiting this cutleaf toothwort. Notice how the ant isn’t carrying much, if any, pollen on its body.
I watched a small group of ants climb across these flowers for a few minutes, wandering up and down the stems, and across the various structures of the flower. I noticed two interesting features: the ants were definitely eating the pollen, grazing on each anther and then eventually walking down the stem to, presumably, return to their colony. And despite walking all over pollen-laden flowers, they appeared remarkably clean, unlike a bee which would have been covered with pollen. My hunch is that these ants were doing little to pollinate this flower and were instead looking for an easy lunch.
With their reproductive cycle happening so early in the year, when there is a relative paucity of active pollinators, spring ephemerals have had to adapt. Erythronium americanum or yellow trout lily is a great example. For starters, look at the sheer amount of pollen this guy produces.
A yellow trout lily in full bloom. Notice the reddish-brown pollent.
Each tiny reddish-brown dot is a pollen grain.There must be tens of thousands on just this one flower. Scroll back up to the other photos and compare (the other flowers produce yellow pollen); trout lily simply has them beat when it comes to sheer amount of pollen per flower. If we look inside the flower, you can see how it gets everywhere.
The little brown flecks on the petals and pistil aren’t dirt, that’s pollen
Another feature I’ve noticed, and this is not unique to Erythronium, or even spring ephemerals, is that the anthers do not all open up at once. Often a couple are laden with pollen while the rest remain barren for several days. My guess is that this is not just happenstance, but that it helps protect the flower from losing all its valuable pollen to thieves, like those ants, or heavy rain storms which may wash the pollen away.
Erythronium, much like Claytonia virginica or spring beauty, is also happy to eschew sexual reproduction entirely, instead relying on corms and stolons to form dense colonies. In fact, given that it can take 4 or more years for a trout lily to reach maturity, this is their primary means of reproduction. In the pictures above, you can see the many distinctive mottled leaves of trout lily in the background. Each plant only produces a single pair of leaves, so many leaves means many individual plants. Almost of all these are likely the result from vegetative reproduction. Here’s Claytonia doing the same thing at one of the raised beds at our Wild Plant Nursery:
A dense colony of spring beauty, likely almost entirely from vegetative reproduction.
Claytonia, is often the first spring ephemeral I see every year, and it also gives me a visual cue as to when spring-ephemeral-watching season is coming to an end. You may begin to see tiny bright orange dots appear on its stems and leaves. A few at first, and eventually covering entire colonies. This is Puccinia mariae-wilsoniae, the aptly named spring beauty rust.
Spring beauty rust attacking a spring beauty. You can see the open sori where it has released spores.
This native pathogen sweeps through spring beauty colonies, usually after the plants have flowered and are beginning to die back. Sometimes, this infection will cause dramatic deformations that resemble Buddha’s hand citrus (Wikipedia link, if you don’t know what I mean). The fungus generally doesn’t kill their host plants entirely -- just the top growth -- which will then re-emerge next spring.
So there you have it, a quick, close look at the lifecycle of some of our native spring ephemerals. I’m hoping to do more of these blog posts featuring my own photography and observations of native plants and plant communities. Where appropriate I’ll cite other sources I’ve consulted, but mostly these will be comprised of my own observations and educated guesses about what I’ve seen. If you want to share your own knowledge, please do so in the comments section here or on our Facebook page!
(1) Spring Wildflowers of the Northeast: A Natural History
By Carol Gracie pp. 59-63