Many years ago a friend wrote a story featuring Lilac trees. We objected that lilacs were shrubs, not trees, but apparently we weren’t aware of Syringa reticulata, or the Japanese tree lilac. A similar tree, the Peking tree lilac was at one time considered a separate species Syringa pekinensis although some now consider it subspecies of the Japanese Lilac tree.
Both trees have origins in Asia, most notably Japan, China, Korea, and a part of Russia. Possibly Japanese tree lilac is more common in the United States. The USDA lists it primarily as a tree introduced in New York, three New England states and Wyoming! The national champion tree is found in Massachusetts. Oddly, according to the USDA, the Peking version has only been introduced into Pennsylvania. Most sources mention the trees are often used as landscape accents and street trees. There are numerous Japanese Tree Lilacs in New York City, with fewer Peking Tree Lilacs. The Japanese variety is a featured tree in Central Park.
The genus Syringa includes the common lilac as well as about thirty other varieties. The Japanese tree lilac is said to be the only member of the genus that attains tree status. This would seem accurate if the Peking tree lilac is considered a subspecies.
The later blooming of the white flowers appears to be the main attraction of these trees, although they are also said to be drought and pollution resistant. The trees in Fort Collins have been flowering for a week or so, making them concurrent with the Catalpas. Larger trees are also valued for their shade canopy.
Various authors disagree about the scent of the trees, some saying it is unpleasant, others that it has little to no odor and others saying the Peking tree scent is that of honey. Before the trees stop blooming, you’ll have to smell for yourself and decide.
The major difference between the two varieties seems to be the bark, with that of the Chinese Tree Lilac, an alternate name along with Pekin Tree for the obvious specimen, being reddish and peeling later in the year. The strips of bark look to me like someone has wrapped the tree in packing tape.
As with many other aspects of trees, there is controversy over this small species. Some sources are concerned the trees are invasive. Other areas of the country from cities in Massachusetts to the state of Wyoming note them as underused trees. Illinois considers the Japanese Lilac Tree as low risk of invasiveness.
To find the marked trees in the park, turn from Mulberry Street onto Sheldon Drive and park close to the intersection with City Park Drive in front of the Arm Walking exercise station. Directly east are the two trees pictured in the photo with the bench. C181 Japanese Tree Lilac (Syringa reticulata) is the smaller tree to the south. The larger tree to the north of the bench is C187 Peking Tree Lilac (Syringa pekinensis). A larger version of the latter tree, D212, which I believe was planted in the 1960s, can be seen on the northwest corner of Mulberry and Sheldon.
A cultivar of the Japanese tree lilac, E4 Ivory Silk Japanese Tree Lilac (Syringa reticulata Ivory Silk)
is viewable in front of the Parks Department building at 413 S. Bryan. This memorial tree is directly in front of the building. The state of Washington suggests this variety as a smart addition to the Pacific Northwest Garden.