The word “sumac” comes from the medieval English term sumach, which originates from the Arabic summaq (سماق), in turn derived from the Syriac summaqa, meaning “red,” in the 13th century. The Greek term ῥoῦς (rhous) is where the genus name Rhus originates.

Description

Sumac plants are trees and dioecious shrubs in the Anacardiaceae family that grow to a height of one to 10 meters. While some species have trifoliate or simple leaves, most species have pinnately compound leaves. The blooms are tiny, greenish, creamy white, or crimson, with five petals, and they are arranged in dense panicles or spikes that are between five and 30 centimeters long. When fully grown, the crimson, thin-fleshed drupes are covered in varied degrees of hair and grow into thick clusters at the ends of branches, which are frequently referred to as sumac bobs. Sumacs propagate by rhizomes and seeds, which are dispersed by birds and other animals through their droppings to produce massive clonal colonies.

Taxonomy

The taxonomy of the Rhus genus dates to 1825, when Swiss botanist Augustin Pyramus de Candolle proposed a five-sectioned subgeneric classification. With more than 150 species, Rhus was the largest genus in the Anacardiaceae family, when it reached its maximum circumscription.

Cultivation and uses

Wild white sumac (Rhus coriaria) is present in the mountains of the Kurdistan Region, and red sumac (Rhus typhina) is cultivated in central and southern Iraq for culinary usage. Many species are bred for ornamental purposes, such as smooth sumac (Rhus glabra), small leaf sumac (Rhus microphylla), and fragrant sumac (Rhus aromatica).

 In food

The dried fruit of some species of sumac is pulverized to create a crimson spice that is popular throughout the world and has a sour flavor. In addition, the fruit can be used to make a classic “pink lemonade” by steeping it in water, straining to get rid of any hairs that could irritate the mouth or throat, and occasionally adding sugar or honey as a sweetener. High concentrations of malic acid give sumac its acidic flavor. 

Rhus coriaria fruit, or drupes, are pounded into a reddish-purple powder that is used as a spice in Middle Eastern cooking to give meats and salads a tangy, lemony flavor. It is frequently added to falafel and used as a garnish on meze dishes like hummus and tashi. The spice is one of the main ingredients of kubah sumakieh, a dish made in Aleppo, Syria. It is added to salads in the Levant, and is one of the main ingredients in the Palestinian dish musakhan. In Afghan, Armenian, Iraqi, Iranian, and Mizrahi Jewish cuisines, sumac is added to rice or kebab. 

In the Middle Ages, particularly between the 13th and 15th centuries, wealthy Western Europeans regularly used sumac in their cooking. Specifically, a stew made from sumac called sumaqiyya was often translated as “macchia” by Europeans.

Dye and tanning agent

Many cultures throughout the world have used the high tannin content of the leaves and bark of the majority of sumac species to make leather. Both the Latin name for Rhus coriaria and the Hebrew term og ha-bursaka‘im translate to “tanner’s sumac.” Some sumacs produce tannins – mostly of the pyrogallol variety – from their leaves. The wood and roots of Rhus pentaphylla and Rhus chinensis, or Chinese Gall, and the leaves of Rhus coriaria are other notable sources.

Sumac-tanned leather is light-colored, pliable, and lightweight. Morocco leather is one kind of leather that contains sumac tannins. When shipping sumac as a fine floury product in sacks alongside heavier cargoes like marble, its coloring property has to be taken into account. Sumac is particularly hazardous to marble, since if it settles on the surface and combines with water, its deep red color can penetrate the marble to a considerable depth. 

Algerian scholar Abdel-Hamid ibn Badis describes a formula for making red ink out of leeched sumac mixed with gum. Sumac dye was used only for the outerwear of the Emperor of Japan, thus making it a forbidden color in imperial Japan. 

Traditional medicinal use

In medieval medicine, sumac was used to treat a variety of illnesses, mostly in Middle Eastern and South Asian societies, where it was more easily obtained than in Europe. When archaeologists excavated an 11th-century shipwreck off the coast of the Greek island of Rhodes in the 1970s, they discovered commercial amounts of sumac drupes. These might have been meant as a spice in food preparation, a medication, or a coloring agent. According to a recent clinical trial, dietary sumac can be used as an adjunct therapy to lower blood pressure in hypertensive patients.

Other uses

Dried sumac bobs are a common fuel source for beekeepers’ smokers. Sumac stems are also especially valuable in traditional Native American pipe-making because of the spongy pith in the core that can be easily removed. In the northern United States, they were frequently used as pipe stems. When exposed to long-wave UV light, dried sumac wood fluoresces. 

Toxicity and control

Sumac can also be dangerous. Poison oak (Toxicodendron diversilobum), poison ivy (Toxicodendron radicans), poison sumac (Rhus vernix), and other species that were once identified as belonging to the genus Rhus can generate the allergen urushiol, which can result in severe allergic reactions. The white drupes of poison sumac differ significantly from the red drupes of the genuine Rhus species.

Goats are a traditional and effective form of control for sumac, since they consume the plants’ bark and inhibit the growth of new branches. Mowing, however, is less effective, given the elasticity of sumac wood. Sumac can quickly regrow following cutting, and spreads via rhizomes, creating clonal colonies from a central mature tree. Root trimming is one way to control the plant’s growth without completely eradicating it.

Yassin Ahmed Rashid is a University Professor and Expert in Botany.