It is not realistic to think that Convallaria majalis does not have to share its habitat with other organisms. Some of  the interactions that it engages in benefit the plant. However, some  interactions are also harmful to the plant. All of these interactions come down to one concept: competition. Organisms participate in these relationships because at least one species in the relationship is benefitting and improving their chances of survival. Symbiosis is the name given to these types of relationships. Depending on how each organism is affected by the relationship, it is also given a more specific title. These titles and definitions can be found more in depth here, with many excellent examples of each type of relationship. But now, onto Lily of the Valley's interactions.

        There are so many interactions that take place with this simple looking plant! Christer Johansson, Wikimedia Commons, 2007.
           Christer Johansson, Wikimedia Commons, 2007.

Convallaria majalis, as stated on the adaptations page, has deadly toxins within all parts of the plant. These toxins are deadly to mammals. This is a major interaction that has allowed Convallaria majalis to be so successful within its niche. Without predation by mammals, there the plant has no need to derive anything more complicated. The adaptations page has much more information on how the poisoning actually takes place. To this date, there are no known mammal exceptions to the toxins of Convallaria majalis. Since many mammals have similar heart mechanisms, the effect of convallotoxin is similar in all mammalian cases of poisoning. Mammals like the Eastern Grey Squirrel (Sciurus carolinesis), the White-Tailed Deer (Odocoileus virginianus), Coyotes (Canis latrans), House cats (Felis catus), and of course humans can all be victims to the wrath of the toxins. The most common victims of this type of poisoning is domesticated dogs.

Mammals are not the only ones that suffer from cardiac glycoside poisoning. Most birds also react severely to the cocktail of toxins within Convallaria majalis. Although birds usually do not feed on toxic plants, there have been cases where pet birds have gotten sick from consuming the plant.

Order: Lepidoptera
There is an order within the Insect or Hexapoda class that has members whose larval forms feed on Convallaria majalis. This class consists mostly of butterflies and moths, and they are parasitic to Lily of the Valley, meaning that they only take from the plant and provide nothing in return. They consume the leaves for nutrition and can often eat entire leaves before the plant can recover from the damages. The toxins that affect mammals have no effect within the bodies of these insects. The Monarch Butterfly (Danaus plexippus) falls in this order. The small number of predators of Convallaria majalis leave its populations relatively unchecked, which only contributes to its status as an invasive species. 

Most plants exhibit a very unique interaction with a fungus. This relationship takes place within the roots of the plant. The fungi will grow on the root of the plant and usually into the cells of the root itself and formed very branched, high surface area structures called arbuscules. The structures allow for the sharing of materials between the plant and the fungus. Both the fungus and the plant benefit from this, an example of mutualism. What does each organism get out of this relationship? The plant can produce lots of sugars, which the fungus is in need of. Plants also provide fungus with a fairly stable and safe habitat. So Convallaria majalis gives up some of its sugar, but what does it get it return? The fungus can provide increased nutrient and water uptake from the soil. In many cases, it is thought that plants would not be able to survive with out the help of their fungus counterparts. Who knew that something that can't even be seen without microscopy and a well-trained eye could be massively important in nature! Take a gander at the image below and see if you can spot the web-like structures growing with in the cells of this plant.

    Mycorrhizae within a plant root. Msturmel, Wikimedia Commons, 2006.
        Msturmel, Wikimedia Commons, 2006.

Time for the REALLY fun stuff! Head on over to fascinating facts to learn more about Convallaria majalis and its amazing ways.