Mountain Ash, Rowan
Sorbus spp.
By Martin (Mort) Schmidt for Simply Living
Mountain Ashes are a lovely little tree, especially when they bear their distinctive red-orange berries. The common name often used in Europe, “Rowan”, is derived from the Scandinavian word for “red”. But they aren’t ashes.
Mountain Ashes (Sorbus spp.) are limited to the northern hemisphere. There are approximately 75 species, two of which are native to the eastern U.S. The description here applies to Ohio’s natives, Northern Mountain Ash (aka Showy Mountain Ash, Sorbus decora) and American Mountain Ash (S. americana). William Carey Grimm’s The Illustrated Book of Trees indicates that both can be distinguished from European species by their sticky terminal buds.
Mountain Ash leaves are alternately-arranged and pinnately-compound. Alternately-arranged leaves and branches are not directly across from each other, while oppositely-arranged ones are. Pinnately-compound leaves have leaflets attached at various points on the stem, while palmately-compound leaves have leaflets attached at the same point.
The 9 to 17 ovate leaflets are 1 to 3 inches long, pointed, and sharply toothed, and are attached to the stem with little or no stalk. As Mountain Ashes are in the rose family, their white flowers have 5 round petals, and their ¼-inch red-orange berries have 5-pointed calyces. The flowers and berries occur in dense clusters that make Mountain Ash highly conspicuous, especially when berries are present in late summer or early fall. Mountain Ashes are monoecious, and have male and female flowers on the same tree.
The brown or dark gray bark is thin and smooth, with conspicuous horizontal rows of pores (lenticels).
Mature American Mountain Ashes typically have a height of 30 feet and a trunk diameter of approximately 8 inches, according to The National Audubon Society’s Field Guide to North American Trees, Eastern Region. Ohio’s Champion website has no listing for Mountain Ashes.
ID Summary: Small tree with alternately-arranged, pinnately-compound leaves with 7 to 19 toothed leaflets, and conspicuous clusters of red-orange berries with 5-pointed calyces in late summer.
Similar Trees: Mountain Ashes can be difficult to distinguish from sumacs. But Ohio’s native Staghorn Sumac (Rhus typhina), Smooth Sumac (R. glabra), and Winged Sumac (R. copallinum, aka Shining Sumac) have much smaller berries that are held in upright cones. Staghorn Sumac has hairy twigs, and Winged Sumac has shiny leaves and distinctive fin-like protrusions on its stems. Furthermore, Mountain Ashes are far less common in Ohio and are mostly seen in landscaping.
Northern Mountain Ash and American Mountain Ash are native to the northeastern U.S. According to Lucy Braun’s The Woody Plants of Ohio, Northern Mountain Ash occurs in Geauga, Ashtabula, and Trumbull Counties in northeastern Ohio.
Mountain Ashes are found in moist, well-drained soils, preferably acidic. They do best in cooler climates in areas with full sunlight. The soils in western Ohio (overlying Ordovician, Silurian, and the western half of the Devonian-age bedrock) are generally alkaline, due to the presence of limestone and dolomite. Mountain Ash prefers acidic soils typical of eastern Ohio (overlying eastern Devonian, Mississippian, Pennsylvanian, and Permian bedrock), due to the presence of shale and sandstone. The Spruce says that Mountain Ash has low salt tolerance and does poorly in hot, humid climates.
The Columbus, Ohio Street Tree Inventory does not list Mountain Ash among the city’s 80 most common trees.
The Tree of the Month article normally quotes the Wood Database for information on wood hardness and density, but the Mountain Ash on that website is in genus Eucalyptus, not Sorbus, and grows in Australia. (The common names of plants and animals are inconsistent, and sometimes used for multiple species, which is why Latin names are preferred in scientific literature). Romeyn Beck Hough’s Handbook of the Trees of the Northern States and Canada provides a density for our Mountain Ash, Sorbus, equivalent to 0.54 g/cc, on par with that of Black Cherry (Prunus serotina), which is moderately hard. Mountain Ashes of the genus Sorbus are too small to be of commercial use. But several sources, including Fred Hageneder’s The Meaning of Trees describe Rowan wood as very hard, and say it was used to make spinning wheels, tool handles, stakes and pegs, and divining rods. The difference in wood hardness might differ between species of Sorbus. Several other trees in the Rose family, including Apple, Serviceberry, and Hawthorn also have very hard wood.
The Peterson Field Guide to Medicinal Plants and Herbs of Eastern and Central North America indicates that American Mountain Ash fruits were allowed to rot and made into a strong cider. The European Mountain Ash was used to treat hemorrhoids, urinary problems, indigestion, gallbladder ailments, angina, and other coronary problems.
Various sources indicate that the berries are unpalatable by themselves, but are used for making jams and jellies. Henry David Thoreau said that, “They are exceedingly bitter and austere to my taste, and I do not see how the birds can eat them, but the fact is they do not chew them”.
According to Bates Canopy, Mountain Ash contains high levels of antioxidants. Phenolic and ascorbic acids in the fruits have anti-inflammatory properties, which protect against tumor growth.
According to the Native American Ethnobotany Database, Sorbus Americana was used by the Natives for:
- Algonquin – Decoction of bark taken for colds and to treat depression and weakness,
- Algonquin – Fruit eaten as food,
- Iroquois – Fruit eaten to improve digestion,
- Malecite – Infusion of bark for analgesic after childbirth,
- Malecite – Poultice of burned bark for treating burns,
- Micmac – Bark or roots used to treat “mother pains”,
- Micmac – Bark used to treat boils,
- Micmac – Infusion of root for colic,
- Montagnais – Decoction of bark taken to stimulate the appetite,
- Montagnais – Fruit eaten as food,
- Ojibwa – Parts of the tree were used to treat STDs,
- Ojibwa – Wood used to make ribs for canoes, snowshoe frames, and lacrosse clubs,
- Ojibwa – Fruit eaten as food,
- Penobscot – Plant parts used as an emetic,
- Cree, Woodlands – Decoctions used externally to treat rheumatism and backaches.
Our Native Trees by Harriet L. Keeler tells us that birds don’t like the taste of Mountain Ash fruits, and that they avoid them if any other food is available, but some sources indicate that birds relish them. The fruits are said to persist on the tree well into winter, so perhaps their popularity increases as food becomes scarce in late winter. Squirrels and other rodents also eat the fruits. In their northern range, moose browse on Sorbus twigs.
The 5 points on Mountain Ash’s fruits form pentagrams, which were considered to provide protection in European culture. So people planted Mountain Ashes, or Rowans, in front of their houses to ward off evil. When the colonists moved to America and found Mountain Ashes, they saw them as highly auspicious, offering protection from witches, crop failures, and other problems.
Rebecca Rupp’s Red Oaks & Black Birches discusses the legend in which Rowan wood was used to construct the True Cross. However, she points out that this distinction is also attributed to cypress, cedar, pine, and holly. Alexander Porteous’ The Forest in Folklore and Mythology adds fig, oak, elder, and ash. Flowering Dogwood and Quaking Aspen are often cited in American lore, as sources of wood for the crucifix.
The Druidry.org website has a lot to say about the traditional beliefs surrounding Rowan in Europe. One common saying was, “Woe to those with no Rowan Tree near”. They go on to list a number of ways in which Mountain Ash protected people:
- Trees protected people from lightning,
- Branches over the doors of cattle sheds protected livestock,
- Trees in graveyards prevented the dead from walking,
- Rowan walking sticks prevented harm and protected against getting lost,
- Boats made of Rowan were protected from storms and going off course.
Druidry.org goes on to say that “Forked branches were used as metal-diviners, much the same way Willow is used for water divining.”
Tree Spirit Wisdom says that, “The European Rowan, Sorbis aucuparia, is known as the ‘traveler’s tree.’ It was believed to help people if they were lost on their journey. The hard, dense wood of a Rowan was used to carve walking sticks that supported those who followed their souls calling……..Its red fruit, which also inspired its genus name Sorbus, was associated with drops of blood from the gods Woden, Odin and Zeus. For this reason, it was considered bad luck to cut down a Rowan tree. In Norse mythology, Thor (God of Thunder and Agriculture) was saved from drowning by grabbing onto a Rowan branch as it leaned over to catch him”.
Tree Spirit Wisdom also tells us that, “In the time of Plato, the Rowan ‘sorb apple’ or fruit of the sorb tree was pickled and eaten in halves. In Plato’s Symposium, the sorb apple was a metaphor for cutting the original spherical nature of humans, as both male and female, in half. This separation created the longing to find our other ‘half’ as if that part of our soul had left us”.
According to Our Native Trees, clover, Saint John’s Wort, and other plants ward off witches, but none are more effective than Rowan. The book quotes an ancient poem,
“Their spells were vain; the hags returned,
To the queen in sorrowful mood,
Crying that witches have no power
Where there is roan-tree wood.”
Simon Will’s A History of Trees also discusses magical powers that were attributed to Rowan trees. Standing near a Rowan was supposed to prevent injury from lightning, while stirring milk with a Rowan stick helped butter to form. In Wales, ale was often flavored with Sorbus berries. Rowan twigs formed into a cross and bound together with red thread offered especially powerful protection from witches.
The most powerful of the powerful is the Flying Rowan, according to Alexander Porteous’s The Forest inFolklore and Mythology. A Flying Rowan is one that grows in the crotch of another tree, after its seed was dropped there by a bird. A Norwegian story has it that a farmer’s Rowan-wood plow was the only one that could overcome a troll’s curse and plow straight furrows.
Mountain Ash has few practical applications, aside from repelling witches, but the beauty of its flowers and fruits more than compensate.
You can also listen to my talks on Ohio Broadleaf Tree Identification on YouTube, Part 1 and Part 2.
