What's that Blob in the Tree?

Now that the tree branches are bare, you may notice dark blobs in the branches and wonder what in the world they are. Here in Kentucky, there are two options to choose from - either mistletoe or squirrel nests. It's easy to tell them apart, since you can see sky through the branches of mistletoe and if the light is good the green leaves are clearly visible.

The word "mistletoe" is derived from the Anglo-Saxon words, "mistel" (dung) and "tan" (twig) -- misteltan is the Old English version of mistletoe. It's thought that the plant is named after bird droppings on a branch. People used to believe that, rather than just passing through birds in the form of seeds, the mistletoe plant was an inherent result of birds landing in the branches of trees. The birds also help spread the seed by wiping their beaks on the tree bark to clean off the sticky seeds after they've eaten. The seeds are sticky because of the juice inside the berry, which helps the seeds stay in the tree rather than falling to the ground. Within six weeks, the mistletoe plant begins growing, although it takes five years to flower.

Mistletoe (Phoradendron flavescens or Viscum album) is a parasitic plant that grows on trees, particularly hardwood trees like oak and apple. A parasite is a plant or animal that needs another plant or animal to survive. As mistletoe grows on a tree its roots invade a tree's bark, which allows mistletoe to absorb the tree's nutrients. Sometimes, mistletoe can harm a tree and cause deformities in a tree's branches, but usually it doesn't kill its host. If the host dies, the mistletoe dies. Mistletoe produces its own food by photosynthesis and is able to live on its own, although it is mostly found in trees.

The dark colored solid blob probably belongs to a squirrel. When I teach classes at the Nature Preserve about animals who live in trees, children often expect squirrels to live in a cavity in the tree trunk, when actually they build nests of leaves between sturdy branches. Do squirrels hibernate in winter? No, they stay in their nests to conserve body heat in cold weather, but are active all year. In fact, squirrels mate in the late Winter or very early Spring. This time may vary with location, and the weather conditions. The best time to see a squirrel's acrobatic skill is, during the "mating chase".

Most squirrels eat nuts, seeds, grain, and fruit.   By far their favorite food would be nuts, followed by sunflower seeds.   Urban squirrel have adapted to eat just about anything,  including pizza,  luncheon meats and all forms of snack foods. Squirrels have been known to eat bird eggs, but this is a last resort. Gray and Fox squirrels hide their food in many places,  so if another squirrel or animal were to find it,  the entire year's supply would not be lost.  Sometimes they hide food temporarily, until they can move it to a more convenient location.  This is called "scatter hoarding". Of course, squirrels help plant trees when they do not eat all the buried acorns.

Mast is an important diet component of many wildlife species. Mast is the fruit of a tree or a shrub and is called “hard” (acorns, hickory nuts, walnuts, etc.) or “soft” (fleshy fruits of dogwood, blackgum, black cherry, etc.). Some of the most important trees and shrubs that produce mast are the oaks,dogwoods, hickories, black cherry, blackgum, beech and maples. The oaks are probably the single most important group of trees for mast production for wildlife. For squirrels, bears, wild hogs and to a lesser extent deer, oak mast appears to be the most important factor influencing reproduction. Following years of good mast production, reproduction, survival and population levels of these wildlife species are high. This has been a good mast year, as evidenced by the large piles of acorns under my bushes and on the driveway!

Naturally yours,

~denapple

Golden Ginkgo Trees

Many trees turn bright yellow in the autumn, but one of my favorites is the bright yellow Ginkgo tree, found in many locations since it is a popular landscaping tree. But this tree is unique in many ways. The trees adopt a very independent attitude to turning. Some trees will be yellow, and semi-bare, while others are still green, and still others exhibit an odd patchwork, with some yellow areas, some green. And the show doesn't last for very long, because once an individual tree decides to drop, it's all over in a few days.

The leaves are unique among seed plants, being fan-shaped with veins radiating out into the leaf blade, sometimes bifurcating (splitting) but never forming a network of veins as a maple tree for example. Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as dichotomous venation. Click this photo for a closer look.

The Ginkgo is known as a living fossil, with fossils recognisably related to modern Ginkgo from the Permian, dating back 270 million years. Plant classification is a bit complex, but in evolutionary order, after the mosses and worts (no proper roots or water transport), and ferns, horsetails, and club mosses (proper roots, bear spores), we get the two big divisions, the gymnosperms ('naked seeds') and angiosperms ('covered seeds'). Angiosperms are all the plants that people put in gardens, like cabbages and dahlias. Almost all surviving gymnosperms are conifers - Christmas trees, and so on - but the group also includes cycads (tropical plants rather like palm-trees), and of course the ginkgoes. This plural is a bit odd, since there's only one species of ginkgo left now, but things were different in the days of the dinosaurs. There were many species then, with a range of leaf shapes.

How did the Ginkgo come to be in your yard? From China it was transplanted to Japan, probably by Buddhist monks in the 1100's. Englebert Kaempfer, a German botanist, wrote about it after his stay in Nagasaki (1690-1692), and by the 1730s ginkgo seeds had been brought to Holland, and a tree was growing in Utrecht. It could then be propagated by layering (since the seeds take many years to start forming), and so spread across Europe. After the War of Independence it arrived in American in 1784, where it became common.

 

Ginkgo trees have separate sexes, just like mammals, and only the female (of course) bears fruit, which is a very important thing to know. If you want to plant one in your yard be sure to get a male tree. The female tree bears seeds every other year, and they smell like vomit! Several such trees grew along the sidewalks next to a class building when I was at Ohio State University, and if you stepped on the fallen fruit, your shoes stank for days.

In addition to its use as a delicacy, the ginkgo has been used in traditional Chinese medicine, and is enjoying popularity now in "alternative" health circles. (Perhaps half of the websites about the ginkgo are herbal remedy sites of one sort or another.) Generally infusions from the leaves are used, and these are claimed to improve one's brain power to an amazing degree. They do contain substances which are known to improve circulation to the brain in particular; rather less believable is the original Chinese theory that the leaves must be good for the brain, because they resemble a section of the brain in shape. Also fascinating: a good number of sites advocating use of ginkgo leaf infusions claim that the seeds are toxic. That's good enough for me - I won't eat them!

Naturally yours,

~denapple