Rose family – What Tree Where

Swedish Whitebeam-Don’t Let the Tag Fool You!

What do I know about the Swedish Whitebeam tree? It belongs to the genus Sorbus which is in the rose family. This large family of over 3000 species includes apples, cherries, plums, pears, and mountain ashes, as well as the flowers known as roses. Mountain ash trees are members of the same genus (Sorbus) as white beams and therein may lie some of my confusion in finding this speciman. I kept returning to the area on the tree map where this species was said to be located, but the unmarked trees in the area seemed to be true ashes and elms. The one unusual tree had leaves that were completely wrong. I thought I knew the smaller deciduous tree was an Oakleaf mountain ash as I’d read the tag the year before.

P9280006_01 — The darker green Sorbus intermedia in forefront

As the name implies, the Swedish whitebeam is not native to North America. As it doesn’t appear on the USDA maps, it must not be considered significant in the United States, although Toronto mentions it on its parks pages. In Great Britain it is suggested as a street tree. One source suggests it can withstand harsh conditions, is hardy to zone 3, and grows on Shetland Island. It may also be a tree useful for birds and bees.

The wood of the whitebeam has been used for handles, wheels and cogs. According to a few sources, the berries have been used to make bread and jam or used similarly to raisins. They may also be distilled into spirits.

As mentioned above, some of the confusion in finding this tree may be related to some of its attributes. Whitebeam are related to mountain ash trees and rowans. Tree Names lists fifty species of whitebeam, but also mentions whitebeams and rowans naturally hybridize. Some authors hypothesize that Swedish whitebeam are a hybridization of mountain ash and two other species or are derived from the Finnish whitebeam. With all the mountain ash genes involved, it isn’t surprising the sign on the Swedish Whitebeam

P9280001_01 — Swedish whitebeam with correct latin name on label.

displays Oakleaf Mountain Ash as a common name along with the latin name of Sorbus intermedia, or that of the Swedish Whitebeam. Seems like it just continues the confounding nature of the Sorbus genus!

P9280003_01 — The leaves of the Swedish whitebeam looking very similar to that of the Oakleaf mountain ash.

And why the two trees are so easy to confuse:

The tree on the Fort Collins City Park Self-Guided Tree Tour was planted in 1994 with a 2″ diameter. Although they are supposed to have white flowers in Spring turning to red berries in fall, no berries were visible in late September. This tree may live to 134 years.

To locate tree D192 Swedish Whitebeam (Sorbus intermedia), go to the southwest corner of the intersection of Sheldon and City Park Drives. This section is lined on the north and east by elms and ash trees with conifers making up the other boundaries. In the center are two conifers, the Engelmann Spruce and a Baker’s Blue Spruce. Of the three deciduous trees, the Swedish whitebeam is the most southerly and smallest. It is also the only one with a visible tag.

Mayday tree: Inadvertent Meaning to a Name?

In Scotland this was once known as the Witches’ Tree

The Mayday tree is a member of the rose family, in the same genus as cherries and plums. Another common name for it is European Bird Cherry. This name gives a clue as to its origin. According to a Canadian website, it grows in countries near the Arctic but is native throughout Europe where its berries attract birds. It has been introduced in the US and is most prevalent in Alaska and parts of the east, including Canada.

The tree is grown as an ornamental in the states. It is on more than one list of preferred trees for Colorado and is included as a good choice for the Front Range by the Colorado Tree Coalition.

There is no doubt that it is a gorgeous tree when it blooms. It also has a distinctive, spicy smell which wafts over large areas.

The lovely scented flowers of this tree become dark colored “cherries,” also called

P5080079_1 — Flower Clusters of the Mayday Tree

chokecherries, although the berries usually eaten in the US with that name are from the same genus but a different species. These are said to be very bitter, but may still be made into jams and jellies. One source says they can be used to make cherry brandy. Mention is made that Koreans eat the boiled leaves.

The various parts of the tree have been used for the usual medicinal remedies for internal problems such as gall stones; colds, and fevers. A more unusual mention is a concoction of an eyewash for conjunctivitis. The leaves and berries may be made into green dyes, as well as a reddish dye for fishing nets. Some sources say the lumber is prized in woodworking, but the Wood Database doesn’t list it.

Although this tree does not currently appear to pose a threat to the lower 48, it has become invasive in Alaska. It may cause difficulty in growing other shade trees as well as adversely affect the willow population. Moose often feed on willow trees, possibly decreasing a food source. The leaves, twigs, and drupes contain hydrogen cyanide and can be deadly for horses and other large animals. Recently this has caused problems for moose. Eaten in small amounts, humans normally will not be harmed by the hydrogen cyanide in the berry’s seeds.

A photo of the trunk of the tree is included to help in identification.

D74 May Day Tree (Prunus padus) is located on S. Bryan Drive between Oak Street and City Park Drive. It is very close to the street, across from the playground. This specimen was planted in 1993.

As indicated, this tree is called variously the May Day Tree, Mayday tree, European Bird Cherry, Cluster Cherry, and Hagberry. (The Sibley Guide to Trees.) At first I thought it was named the May Day tree as the flowers bloomed around the beginning of May. After reading of the danger to native trees in Alaska and the poisoning of large mammals, I wonder of it was inadvertently given a name mimicking a call for help!