City Park Arboretum – What Tree Where

Arborvitae; The Tree of Life or at Least One of Them!

What do Harry Potter and Arborvitae have in common?

I swear I never heard of Arborvitae until this year, but when I stop to think about it, I believe we had some growing in our front yard until we took them out to change the landscape. They were annoying. The branches bent under heavy snow or ice. Arborvitae are native to the eastern United States and Canada where they may be called Eastern White Cedar or Northern White Cedar.

Arborvitae means tree of life in Latin, but unfortunately, in common parlance, other varieties of trees are referred to as the tree of life. The baobab and coconut both may carry that appellation while a specific mesquite tree in Bahrain also is called that.

Thuja occidentalis may have been the first specimen tree to be transported and transplanted to Europe and has been grown there since the 1500s. It was given the name Tree of Life when Jacques Cartier learned from the Iroquois that a tea made from its leaves would cure his men of scurvy. There are five species in the genus, but only two of them are native to North America. The other three species are native to Asia.

Native Americans not only used the leaves for the nourishing tea, but as bedding, and the lumber was used as canoe frames. Many parts of the tree were used for other medicinal purposes, including as an abortifacient. Log cabins have been built from larger specimens, partly due to the wood’s insulating properties and rot resistance. This last property also contributes to the wood’s use as fence posts. Arborvitae are important for wildlife as both a food source and shelter.

Although today this species is most often used in the landscape, it can be a long-lived tree with one of the oldest known thought to be over 1000 years. The Wintergreen Arborvitae variety seems especially well suited as a privacy screen while other varieties planted in a row are used for windbreaks.

P1110617 — A lone Wintergreen Arbor Vitae

According to some sources, the tree has antibacterial, anti-fungal, and anti-viral components. Alternative medicine practitioners may suggest its use during radiation. An essential oil is made from its steam distillate, which is most commonly used to burn off warts. According to the site cited above, the essential oil is up to 65% thujone, Thujone, also a component of absinthe, is considered toxic and the use of the oil, especially ingested, is not recommended. Apparently thujone is mentioned in at least one of the Harry Potter books and caused quite a stir with the religious right!

Two of the three arborvitae in City Park are near each other. A94 Wintergreen Arborvitae (Thuja occidentalis Hertz Wintergreen ) and B96 Techny Arborvitae (Thuja occidentalis Techny) are located along Roosevelt Drive between Oak Street and City Park Drive. Both are in the field on the east side, across from the trolley station and tennis courts. The Wintergreen Arborvitae is closer to City Park Drive, near the tall conifers. The Techny is directly across from the trolley station.

The third tree, E62 Brandon Arborvitae (Thuja occidentalis Brandon) is between the ditch and the miniature Train Station, just past the rock wall that runs along City Park Drive, across from Tico’s.

P1150010 — Close up for the leaves on Thuja.

P1150001_2 — The leaves of the three Arborvitae in City Park

Engelmann Spruce– A True Native of Larimer County

The oldest Engelmann Spruce is over 900 years old

It seems to me one of the most confusing aspects of spruce trees is their many alternate names. One of the names for the Engelmann Spruce is white spruce, as well as silver spruce and the generic-sounding mountain spruce. At a glance, the various species look very similar, too. The Engelmann Spruce (Picea engelmannii) is a native of North America. Listed in Flora of Colorado (Jennifer Ackerfield, 2015) it is native to Colorado as well as Larimer County! Unlike the White Spruce written about last week, internet sources concur this one is a native and show its range being the western part of the continent, south to the New Mexico/Texas border and north to the British Columbia/Yukon border. Possibly the confusion with the white spruce is due to the two trees hybridizing? The Gymnosperm Database mentions that the oldest Engelmann spruce is in Colorado and has attained at least 911 years of age.

PB290008 — White Spruce needles and cone on the left, Engelmann Spruce needles and cone on the right.

The fine needles on the twigs and branches of the Engelmann spruce are much more evenly spaced than those of the white spruce, reminding me of a bottle brush. From a distance, this is hard to distinguish. When examined closely, the spruce cones also have subtle differences; the ends of the Engelmann spruce cones appear to be toothed. Comparing the tagged park specimens, the cones of the Engelmann are also somewhat larger than those of the White Spruce. The Engelmann spruce is the second most common tree used for the Capitol Christmas tree with nine appearances since 1970.

The New York Times Style Magazine of December 3, 2017 short article “Chasing Pine” discussed a number of edible uses of conifers, including the historical spruce beer. Modern chefs make pine ice cream, pine aioli, and custard. Others use a spruce oil in drinks, Some sprinkle a spruce-sugar concoction on cookies.

The Englemann Spruce listed on the tree guide (D193) is at the Southwest corner of City Park and Sheldon Drive. You can access this corner by turning onto Sheldon Drive from Mulberry and parking near the intersection with City Park Drive. That corner of the park is lined by deciduous trees on the eastern and northern edges. Numerous conifers form the south edge along the lakeshore. The marked tree sits in front of the larger spruces, between an Oakleaf Mountain Ash and a Baker Blue Spruce. It has a perfect conical Christmas tree shape.

Gingko Tree–Most Unique Tree in the World?

A tree that hasn’t changed in 200 million years

I had no idea. Of course I’ve been bombarded with ads for the wonderful memory properties of gingko biloba although I never tried it. I didn’t even know it was a tree, nor did I know it grew not only in the United States but right in our own City Park. My tree course mentioned there was a single species, family, and phylum for this tree, but it wasn’t until I started to research it that I learned the tree is a living fossil and hasn’t changed in over 200 million years!

According to the USDA map, the Ginkgo tree was introduced to the US. It is not widely distributed throughout the states, but seems to be very popular in New York and four or five other Eastern states. Mississippi also has an affinity for this tree. The Gingko appears to be able to withstand the stress of city living, which might be one of the reasons they are very popular in New York City. According to one source, there are 21,611 Ginkgo trees in the city, a map or which can be seen here.

Once you see a Gingko leaf with its fan-like shape, the trees seem easy to identify. Although there is only one tagged specimen in the park, I’m sure I found a leaf near a denuded tree very far away, too.

P9290012 — Fan-shaped Gingko leaves as they start to turn in the fall.

Gingkos are often called the oldest trees or most unique plant on earth as they are the only species in their class, have not changed much in 200 million years, and have no close relatives. Peter Crane, Dean of the Yale School of Forestry and Environmental Studies, has written a book about the tree, Ginkgo (Yale University Press, 2013) and was interviewed about the tree here.

I did not encounter any seeds from the one tree in City Park, but they are said to be both messy and smelly, producing a compound that is common in rancid butter. Crane says they smell like vomit. Due to this, usually only male trees are planted. I’m assuming this tree is male, although the same source indicated that the trees don’t produce seeds until they are thirty-forty years old.

Similar to the tenet “form follows function” of the Arts and Crafts and other architectural movements, the herbal uses of this tree seem to relate to its biological history. Most of the medicinal uses relate to many problems associated with aging, such as heart trouble, macular degeneration, tinnitus, as well as it best known use as an herb to improve memory. Components of the plant have long been used in Chinese, Japanese, Indian and Indonesian medicine.

For those of you who might like to explore more about this fascinating tree, there is an all-encompassing blog that includes a history of some of the most interesting Gingko trees from around the world, the use of the leaves in art, and even a Gingko lullaby.

To find this tree, also known as the Maidenhair tree, look for A72 on the map. Basically it is across from the entrance to City Park Pool, right in front of the picnic shelter #6 on the corner of S. Bryan and City Park Drive. Without its leaves, it looks much smaller than this picture! P9290007-2