Life is not easy out in the wild. Convallaria majalis cannot escape from its predators or move to find nutrients. It needs support against whatever elements it may face. However, the crucial adaptations that it has takes all of these problems into account and deals with them. I have sorted these adaptations according to what problems they solve for Lily of the Valley.

Escaping Predation: Toxins
Convallaria majalis is fixed in one location; in large part due to having cell walls (which will discussed next). With out being able to run, Structure of convallotoxin. Epop, Wikimedia Commons, 2008.leap, or hide from predators, something must be in place to prevent this plant from being consumed. This something just so happens to be toxins. And not measly toxins that might make you feel a little sick; these toxins are deadly heart-stopping killers. All three of these toxins are actually found within the large central vacuole of the plant (Loffelhardt, Koops & Kubelka, 1979)There are three poisonous molecules found in all parts of the plant and they are all considered cardiac glycosides (Szczawinski & Turner, 1991).

                                                                                                                                                         Epop, Wikimedia Commons, 2008.

These cardiac glycosides disrupt the sodium-potassium adeninetriphophate pump, or the Na+/K+ pump, which aids in the electrical function and nerve firing within the heart and other parts of the body (Lofton, 2005). These three toxins are convallotoxin, convallarin and convallamarin. Each one has a slightly different chemical makeup, but convallotoxin is the most harmful. Out of the naturally produced substances toxins that affect the heart, it is thought to be one of the most toxic  (Szczawinski & Turner, 1991). The chemical structure of convallotoxin is found above right. Directly below is the chemical structure of convallamarin.

Convallamarin Structure. Ron H. Jones, Wikimedia Commons, 2010.When any of these three toxins are consumed by any mammal, the toxins can cause a cornucopia of symptoms. The following, in approximate order of severity, are the most typical symptoms of digitalis-like cardiac glycoside poisoning: Feeling hot and flushed, headache, nausea, vomiting, burning in
mouth and throat, diarrhea, increased saliva production, dilated pupils, abdominal pain, cramping, clammy skin, irregular slow heartbeat, coma, and death (Szczawinski & Turner, 1991). It is important to remember that every part of the plant is poisonous. If the plant is cut and placed in water, the water can also be toxic and dangerous to drink.

 Ron H. Jones, Wikimedia Commons, 2010.

Side Note: Convallotoxin and Medicine
Convallotoxin is not all danger and death. Before the use of Foxglove, another plant that has deadly cardiac glycosides, convallotoxin from Convallaria majalis was used medicinally. It was used as a heart stimulant, in a very small amount. However, doctors also used it as a diuretic. Like stated earlier, it has now been replaced with toxins from Foxglove (Szczawinski & Turner, 1991).
When convallotoxin in ingested in large amounts, like the amount one would ingest if they took a bite out of Convallaria majalis, it is extremely harmful. There are a few treatments that a physician might apply after an individual ingests any of the Lily of the Valley toxins; forcing vomiting or a gastric lavage may be necessary depending on how soon the individual begins to show symptoms (Arena & Hardin, 1974). If they are caught early, this is one of the most effective means of getting rid of the toxins.

Although this plant looks harmless, its extremely toxic adaptation is deadly. But do not think of these cardiac glycosides as the bad guys here! Without them, animals would likely consume Convallaria majalis into extinction, and we would no longer be able to enjoy there immense beauty. So really, we should be thanking these poisonous molecules.

Support: Cell Walls
Since many plants are stationary, they must have a mechanism in place to prevent them from being fragile, easily damaged, and unsupported. One of the adaptations is a cell wall surrounding the plasma membrane of all the individual cells. This cell wall is composed of strands of cellulose intertwining and overlapping. Model of a plant cell wall. LadyofHats, Wikimedia Commons, 2007.What these abundant cellulose fibers result in is a rigid outer covering around each cell that still allows for the exchange of materials in and out of the cell. This feature is unique to plants. Although fungi also posses cell walls, they are made up of a different material, chitin. The walls of every individual cell with in the plant makes for a sound support system within the plant. Depending on what type of cell, the cell wall can be thicker or thinner, and there may even be a secondary cell wall, which is located interior to the primary cell wall if present.
                                                                                                                                              LadyofHats, Wikimedia Commons, 2007. 

Gas Exchange: Stomata
Based on the formula of photosynthesis, we know that oxygen in released as a waste product, but carbon dioxide is needed as well. But how does this oxygen leave the leaf? How does the carbon dioxide enter the leaf? There are special structures located on the leaves called stomata. They are small openings that allow for exchange of gases that can open or close based on if the plant needs to release or take in gases. They consist of two cells called guard cells that are responsible for the opening and closing of the stomata. The process revolves once again around osmosis and material moving and in and out of these guard cells. When the guard cells are turgid, or full of water and there is lots of internal pressure, the stomata will be open. However, when the water exits these cells, the cells lose that internal pressure and close. The result is the efficient exchange of gases within the leaves on Convallaria majalis. On the bottom left there is an example of an open stomata, and on the right is a closed stomata.

  Open Stomata. Brett Pickarts, 2013. Closed Stomata. Brett Pickarts, 2013.
    Brett Pickarts, sent via e-mail, 2013.                                                      Brett Pickarts, sent via e-mail, 2013.

Water Uptake: Roots
Convallaria majalis has to get the water for photosynthesis from somewhere... but where? The simple answer is the roots. But the process involved a little more than that. It involves a little bit more help, help from interactions with other species. The soil is the source of water for the plant, and the roots are responsible for helping take in this water. The water will eventually have to travel up to the leaves... but how?!

Water and Sugar Movement: Xylem and Phloem
How do plants manage to evenly distribute water as well as sugars across the entire plant? Based on Convallaria majalis's nutrition, we know that sugars are made within the leaves. The water found within the ground is taken up by the roots of the plant along with many nutrients (some other species assist in this exchange as well). What we end up with is plenty of water within the roots and a lack of sugar. The leaves have a lack of water and an abundance of sugars. The adaptation set up to deal with this problem is a vascular system. The vascular system consists of two main components: the xylem and the phloem. The difference between these two is the way in which they carry their respective substances. The xylem carries water and nutrients up to the leaves from the roots while the phloem carries sugars down to the roots from the leaves. They are both skinny mostly hollow pathways that allow molecules to flow within them. Each one is equally important for the survival of the plant.

This still leaves us with the question of how the materials actually travel.  The most basic concept behind both is osmosis. Where ever water is less abundant, water will travel there from a place where it is more abundant. A few properties of water help with the movement of the molecules up and down the vascular system. Cohesion, the ability of water to stick to itself, adhesion, water's tendency to stick to surfaces, and capillary action, or the tendency of water to be sucked up when stuck in a closed tube.

In terms of xylem's water movement, it is important to understand transpiration. Transpiration is the evaporation of water out of the leaves, typically in the form of water vapor leaving the stomata. When transpiration occurs, there is an increased sugar concentration within these leaves. With this increased solute concentration within the leaves, a negative pressure is created within the xylem. The reduced pressure within allows water to travel up the stem or body of the plant all the way up to the leaves. The cells that create the continuous tube of the xylem are called the vessel members, which are actually dead at maturity!

Phloem movement cannot rely on transpiration, but it still can use diffusion. First, sucrose enters the cells of the phloem, the sieve tube members, via active transport, meaning energy must be invested into this movement. Active transport is necessary to move molecules against the rules of osmosis, which would be the case here, since sugars are already in high concentration within the sieve tube members. Now that there is a high concentration of sugars within the sieve members, there is a low concentration of water. This means that water will enter this cells via osmosis. Now picture all of these molecules inside of this small closed portion of a tube. This creates an area of high pressure formed in the leaves. Now due to the lack to sugar, and therefore lack of water within the roots, there is low pressure at the roots. The sugar and water will flow from areas of high pressure to low pressure, meaning the sugars will flow from the leaves to the roots. The roots are in need of the sugar, and in order to maintain the pressure system, the sugar must be constantly added at the top and drained from the bottom.

Vascular Bundles in a monocot stem. BlueRidgeKittens, Flickr, 2010.

Since Lily of the Valley is a monocot, the vascular bundles, or packages of xylem and phloem, are scattered through out the stem randomly. These bundles can be seen on the right. The oval, almost face-like structures are the bundles. Notice the random pattern here! Because of this arrangement, monocots are unable to grow in girth, but only in height. Due to this inability to grow in girth (secondary growth), it places a limit on how much primary, or upward, growth can occur. If the plant becomes too tall, the skinny stem will be unable to fully support the plant.

 BlueRidgeKittens, Flickr, 2010.

Reproduction: Rhizomes
The majority of reproduction within Lily of the Valley takes place via structures called rhizomes. The rhizomes are an extension of the roots within Convallaria majalis. The rhizomes actually begin their growth like the roots. The rhizomes are essentially similar to roots, but they store many more nutrients and proteins for the plant to use. The rhizomes push through the dirt through growing by mitosis. These rhizomes will grow fairly parallel to the ground, reaching out to find another place for a stem to germinate. When the rhizome detects that the spot has enough nutrients, it will begin to grow a new stem off of the rhizome. The entire process is that simple! However, it is important to note that due to this type of growth, usually called clonal, there is no difference in the genotypes among the plants (Vandepitte et al, 2010). See where rhizomes fit within the life cycle of Convallaria majalis.

    Close up of Convallaria majalis flowers. Margaret Warren, Margaret's Garden, 2010.
     Margaret Warren, Margaret's Garden, 201o.

Protection from Disease: Divinyl ether synthase (DES)
Here is an exciting extra for you! There was a study done to test for the presence of a certain chemical within plants. The chemical is called divinyl ether synthase, or DES. It is not frequently found, but it is almost unheard of to find this special disease fighting substance within a monocot. Prior to the study, only one other monocot was known to have DES. However, the study revealed that Convallaria majalis does indeed have DES (Grechkin, Latypova, Mukhtarova, & Ogorodnikova, 2008). What does this mean for the plant? Having DES helps fight plant diseases with much less time and difficulty. This adaptation is thought to be part of the reason why Lily of the Valley is such a persistent plant, even when other plants struggle to maintain their lifestyles.

The nutrition page can help explain why some of these adaptations are necessary!