Sassafras (Sassafras albidum) leaves just beginning their growth. But why are they red?
The red coloring often seen in new leaves is because of anthocyanin, a pigment which give those leaves that coloring. As the leaves mature and begin the process of photosynthesis, they gain the green pigment, chlorophyll, which gives them the coloring which we expect.
Seems like magic to me!
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First comes the bubblegum pink of the Redbud (Cercis canadensis) flowers. Now as the blooms drop to the ground the leaves are making their way into the world. The leaves are first blushed with red then to the green we know through spring and into summer. The green indicates the presence of chlorophyll which is a pigment used to absorb energy from the sun.
The red color in the new leaves is the pigment anthocyanin. This pigment and the role it plays in leaves has been studied and it is thought that the red plays a part in protecting the leaves from being eaten. Many mammals, primates excluded, do not perceive yellow, orange and red colors but see them as gray. These mammals, not seeing a green leaf, would not recognize it as a choice for a snack or meal. This same pigment is the one that allows some autumn leaves to turn red, as the amount of chlorophyll diminishes in the leaves of those leaves.
Spring unfurling.
During the summer months the trees around us are covered with green leaves. The green color in those leaves is thanks to a green pigment, chlorophyll, that the leaves use to capture the sun’s energy. That energy is used to change water and carbon dioxide into glucose and oxygen, in a process called photosynthesis. Glucose is used by plants for energy and to create other materials such as cellulose, and starch. But how do we end up with the warm colors of autumn? The reds, yellows and oranges?
The principal pigments that produce color within a leaf are: chlorophyll (green); xanthophylls (yellow); carotenoids (orange); and anthocyanins (reds and purples).
During the summer there is an abundance of chlorophyll as the leaves work to provide energy for the tree, this gives the leaves their green color. As summer winds down trees will pick up signals that the seasons are changing. Those signals? Days that are becoming shorter and cooling temperatures. In response photosynthesis slows and the amount of chlorophyll drops drastically, leaving the other pigments within the leaf more plentiful, changing the colors. Yellows, oranges, reds and sometimes even purples. And we have AUTUMN.
To some degree Smooth False Foxglove (Aureolaria laevigata) is a parasite, depending a bit on its host plant, the mighty Oak Tree. It can be referred to as a partial plant parasite, a semiparasite, or a hemiparasite. This means, it is not entirely dependent upon the roots of an Oak Tree for all its sustenance. This plant has chlorophyll and performs photosynthesis. It’s sort of a parasite. But not entirely.
This is in contrast to plants that are entirely parasitic – holoparasites. A holoparasite does not perform photosynthesis and depends exclusively on their host plant for nourishment. This native to eastern North America, Smooth False Foxglove uses roots called haustoria to connect to the roots of its host Oak Tree to absorb sugars and proteins. Along with its host Oak Tree, Smooth False Foxglove flourishes.
There are so many awesome treasures to be found in the woods. One of those treasures that is right up there near the top of my list is Bear Corn (Conopholis americana). It’s a native to eastern North America.
This is a plant that doesn’t have a speck of the color green because Bear Corn has no chlorophyll. Normally plants use chlorophyll and light to make food. But this plant isn’t able to perform photosynthesis. It’s a parasite on the roots of oak trees and perhaps beech trees as well.
These pinecone looking arrangements are the flowering structures that are sent up after four years of taking in nourishment from the oak or beech roots.
Four years underground taking in sustenance. The flowers emerge in the spring and bloom in a similar manner to other flowers.
Bear Corn is pollinated by flies and bees and is also capable of self pollination. After pollination the blooms are replaced by fruit containing seeds.
In the Shenandoah and Smoky Mountains Bear Corn represents a surprising percentage of the diet of bears, ten to fifteen percent. Deer, raccoon and coyote also eat these plants.
By autumn the fruit which has not been eaten will wither and drop, leaving the seeds to return to the soil to again seek out the oak or beech roots. This Bear Corn plant will continue sending up flowers each year for as many as six years.
