My journey took me along Market to 17th street.  I decided to proceed north up 17th to JFK boulevard.  At the interesection I was surprised to find some American Hornbeam trees lining the street, following a grouping of American Holly trees.  Here’s what I mean:

American Hornbeam (Carpinus caroliniana)

The American Hornbeam tree is native to Canada, down through Texas and across to Florida.  It is a multi-stemmed, deciduous tree that can grow 20′-30′ tall and as wide or even wider as its height.  The tree has an alternate leaf arrangement, with oblong-shaped leaves that can be 2.5″ long and 5″ wide.  They have a dark green color to them, with a doubly-serrated margin.  Interestingly, in the Fall they can be yellow, orange, or red, with variability in color within one tree.  The tree is monoecious meaning it includes male and female flowers on the same plant.  It is easy to identify it by its bark in the winter, which is smooth in texture, gray in color, and has slender, dark brown, and slightly hairy stems.  The base is fluted and the bark can have vertical ridges that are visible.  It is odd because the tree does not transplant very well, but is a great shade tree and park tree.  Unfortunately as you can see, these trees have been engulfed by Christmas lights, to bring attraction out front of the Comcast Building’s cafe. 

American Holly Tree (Ilex opaca)

These American Holly Trees are situated along JFK Boulevard between 16th and 17th streets.  The Holly tree is native to the eastern and southern United States, and is hardy to zone 5.  The trees themselves can reach upwards of 50′ in the United States, however are most commonly found in the 15′ – 30′ range.  They are very pyramidal when they are young, with some branches reaching the ground.  As the trees mature, the branching becomes more horizontal.  The trees feature alternate leaves that range from 1.5″ – 3.5″ in length.  The leaves have short spines and are a dark green color.  Two ways to identify the trees are there small red fruits attaches to stalks on the branches, and the leaves themselves.  The bark is a gray-brown color that remains smooth until the tree has reached full maturity.  As you can see, they greatly beautify the parkway!  

London Plane Tree (Platanus x acerifolia)

Doing a little bit of research, I found that the London Plane tree is a result of a cross between Platanus orientalis and occidentalis.  The trees themselves can grow to be 70′-80′ tall and their spreads generally will match their heights.  The shape of the tree is usually rounded, with branching upright and spreading.  However, in their younger ages, the shape of the tree is more pyramidal.  The leaves are alternate and simple and can be 6″-7″ long and up to 10″ wide on older trees.  The shape is very similar to the maple.  The most easily identifiable feature of the tree however is undoubtedly its bark.  It is very ornamentally attractive, with the bark exfoliating in plates.  This reveals an inner yellow color bark, creating a beautiful composition of color.  It is a great city tree, pollution tolerant, easily transplantable, and very adaptable to any conditions.  This tree in the city is provided with plenty of space for its roots to maneuver, however is limited so girdling may be occurring with a tree of this size.  Overall, it is a beautiful tree for the city.


to be continued…