Bob’s Your Uncle Sumac

One of the first trees to show signs of the draining of chlorophyll from its leaves in the fall is the sumac. As the excision layer grows across the base of the petiole, cutting off the supply of raw materials for making chlorophyll, the big unstable molecule breaks down, leaving behind the yellow-reflecting carotene and red-reflecting anthocyanins. Sumac leaves would seem to have abundant anthocyanins, as they turn a deep, saturated scarlet each fall.

Staghorn in the fall

The most common sumac in the northeastern United States is the staghorn sumac (Rhus typhina). The leaves of staghorn sumac are pinnately compound and each leaflet is coarsely toothed. It is an early succession species that is common along roadsides and in old fields and clearings. Staghorn sumac is dioecious (separate male and female plants) and the female plants carry clusters of drupes that are collectively referred to as “bobs.” They give the staghorn species its name; R. typhina bobs are particularly dense, erect, resembling a buck in velvet, albeit bright red.

The seeds are eaten and distributed by birds. Once a plant grows from a seed it will often spread vegetatively in every direction from rhizomes. These clonal copses are particularly striking in old fields where they may expand radially in a nearly perfect circle. The plants decrease in size toward the periphery (because they are younger), giving the whole clone the appearance of a leafy dome in the warmer months.


Like many early succession species, sumac grows rapidly, often adding a couple of feet in height during one growing season. The wood is soft, weak and greenish-brown. The central pith in smaller trees and large branches in a punky substance that can be pushed or scraped out with a fingernail. It’s frailty makes the wood commercially useless, but the strong banding of the annual rings gives the wood a striking appearance when it is turned into bowls or carved to make ornaments and tool handles.

Many people are leery of sumac because its similar cousin Rhus vernix, poison sumac, is well known for the nasty rash it imparts upon contact with skin. The “poison” members of Rhus are sometimes placed in their own genus, Toxicodendron, and these include poison ivy (Rhus toxicodendron, or Toxicodendron radicans) and poison oak (R. diversiloba).

In my own experience poison sumac is more virulent than poison ivy. I accidentally touched a poison sumac plant being grown in a botanical garden on the campus of the College of the Atlantic in Bar Harbor, and the reaction was an immediate tingling sensation that lingered for hours even though I immediately drench the hand in cold water from a nearby tap. In contrast, a poison ivy rash may not manifest for hours after contact.

Poison sumac

Luckily, poison sumac is rare, confined to extremely wet areas in swamps, marshes, and along the banks of slow rivers. Although its leaves are also pinnately compound, the fruit is white instead of red and the bobs are not as compact as those of R. thyphina.

The global distribution of Rhus is interesting in that the highest concentration of species are in North America and Africa (rather than on adjacent continents). In the Middle East the bobs of R. coriaria are used to make a spice that is used somewhat like paprika, sprinkled over fish, chicken, and hummus, giving it a tart flavor. In North America, staghorn sumac bobs are soaked in cold water and then squeezed to create a tart liquid. When sugar is added it called “Indian lemonade.” North American tribal people mixed pieces of the drupes with tobacco to create smoking blends.

Because of its impressive fall foliage, architectural manner of growth, and its tendency to rapidly fill a space provided, sumac is sometimes used in designed gardens. The individual flowers are small and greenish-white, but the spikes are several inches long and often abundant on the plant, making an impressive show, especially from a distance.

However, the clonal nature of the growth can cause the plant to become invasive and it is difficult to eradicate once established. Every piece of the clone has to be dug up and removed or growth will resume soon and rapidly.


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