Wild Ginger Seed Dispersal

Wild Ginger ~ Asarum canadense


The Wild Ginger was in full bloom in early April this year. The three red sepals form a triangular shaped flower with a white interior. The flowers are hidden below the leaves and often rest on the ground.

"The flower evolved to attract small pollinating flies that emerge from the ground early in the spring looking for a thawing carcass of an animal that did not survive the winter. By lying next to the ground flower is readily found by the emerging flies. The color of the flower is similar to that of decomposing flesh. Whether these flies pollinate the flower or not is in some dispute. Never the less they do enter the flower to escape the cold winds of early spring and to feast upon the flowers pollen. Some of the pollen attaches to their bodies and is taken with them when they visit the next flower."  (US Forest Service, Celebrating Wildflowers)

The method of seed dispersal  is known however. Along with other spring ephemerals such as Bloodroot, the seeds have a fleshy appendage attached to them called an elaiosome. The purpose of the protein rich elaiosome is to attract ants.

Ants love to consume the elaiosome, and discard the seed. They often take the seed back to their nests where the seed is discarded in their nest, ready to germinate the following season.

I thought I'd see how much ants liked the elaiosome. I collected a few seeds and placed them on the ground near an ant. The ant was immediately drawn to the seed and elaiosome.

It consumed the whole elaiosome from one seed, then carried the other one off probably to its nest.

What a great method of seed dispersal, get the seed as far away as possible from the parent plant, and, away from predators such as rodents.

Native Plant of the Week: Nodding Trillium ~ Trillium cernuum

Nodding Trillium ~ Trillium cernuum


The Nodding Trillium is just about to flower in the central Minnesota woodlands. The most common or widely distributed Trillium species in our state, it's a beautiful understated native perennial.

You have to look for the flowers underneath the three leaves as they are hidden below. This Trillium is very similar to Drooping Trillium ~ Trillium flexipes which is less common. Drooping Trillium's flowers are usually above the leaves. See photos and information about the two on the Minnesota Wildflowers site here.

The 1.5 inch wide white flowers are comprised of three petals and 3 green sepals. Not an especially showy Trillium species for the ornamental landscape, it is still a nice woodland native worth seeking out and admiring for its subtle beauty.

We have a small cluster of naturally occurring Nodding Trillium in our own landscape growing in amongst Wild Leeks. Fortunately, this small portion of our landscape was minimally disturbed by previous homeowners.

Nodding Trillium is found in mesic sites in woodlands including cool east facing slopes, and lower lying locations that are seasonally moister. 

Bright red seed capsules form near the end of July into early August. These are much more evident to passers by than the flowers.

Inside the seed capsules are many small brown seeds each with a protein-rich fleshy elaiosome attached to attract ants who are the dispersers of the seed.

Read an earlier post about ants dispersing Trillium seeds and other spring woodland natives whose seeds are dispersed by ants.

Nodding Trillium is native to northeastern North America, see map below for range.

Kartesz, J.T., The Biota of North America Program (BONAP).
2011. North American Plant Atlas. Chapel Hill, N.C.

Ripening Nodding Trillium Seeds

Our Nodding Trillium (Trillium cernuum) seeds are ripening, the capsules are turning ruby red. We have about 16 plants in a clump underneath some Gray Dogwood that have spread significantly since we removed the European Buckthorn from the area.

We were fortunate to have a few 'patches' of significant natives when we bought our house, one being underneath some large oak trees where there is a good quantity of Bloodroot and Virginia Waterleaf and this other area with the Nodding Trilliums, Wild Leeks, Red and White Baneberry, and Fern species.

The previous homeowners never converted these patches to lawn or disturbed them too much, other than allowing invasive species to take hold. These plants have been very helpful in determining what native species to add back that grow in association with them.

My posting in June about Ant Dispersed Seeds talked about how Wild Ginger and Bloodroot seeds are dispersed by ants. Trilliums also fall in to that category having the same fleshy elaiosome that ants think are tasty caterpillars. They carry the seeds off to their nest, eat the elaiosome and dispose of the seed in their 'trash'.

What a great relationship between these spring ephemerals and ants to get the seed as far as possible from the parent plant and buried away from animals who would like to eat the seeds.

Nodding trillium is different from many other trilliums because as the common name suggests, the white flower hangs downward underneath the three leaves.

Like other spring flowering natives, the seeds are best sown right away outdoors before they dry out. As I mentioned before, we usually plant these types of seeds in triangular groupings, so when the first leaves emerge (two years after planting), we know not to weed or pull them out.

Nodding Trillium is native to northeastern North America. See map.

Ant Dispersed Seeds

We have been monitoring the seed capsules of our Bloodroot (Sanguinaria canadensis) and Wild Ginger (Asarum canadense) the last couple of weeks for their pending ripening. Timing is everything if you want to collect the Bloodroot because the seed pod bursts open releasing the seeds in a short time frame.

Unfortunately we were a couple of days late this year for the Bloodroot and found only one pod that still had a few seeds in it.

The green seed pods form underneath the Bloodroot leaf and often remain green up until the time of opening so it is hard to judge when they will burst. The brown seeds are arranged in vertical rows on the interior of the pod and are released to the ground below.

Attached to both the Bloodroot and Wild Ginger seeds is a fleshy appendage called an elaiosome. The elaiosome attracts ants to the seeds because it resembles a caterpillar.

The ants pick up the seeds and carry them off to their nest where they eat the elaiosome and discard the seed, planting it in their nest. 

According to William Cullina in his book Growing and Propagating Wildflowers of the United States and Canada, the seed is discarded in the ants' compost pile where it is nurtured from the nutrients released by the decaying waste and protected from harm from the territorial ant colony.

Like many spring ephemeral seeds, they are best sown in pots or directly in the ground once collected before drying out. We will often collect and plant seeds in clusters so that the following season we see a grouping of seedlings emerge (their first leaves only emerge) - then we know not to weed the seedlings out. It is not until the following year that the true leaves emerge.

Asarum canadense - Wild Ginger Seeds, Seed Capsule and Flower