Tree of the Week: Use the African sumac for shade or perhaps to make beer

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African Sumac -- Rhus lancea

Some trees are valuable, not for one spectacular characteristic, but because they are so utterly reliable doing the mundane job we expect of them. The African sumac, also called Searsia lancea, is a case in point. It will never win an award for great flower display, intriguing smell, striking silhouette or luscious leaves. But when we want a small to medium size, round-headed evergreen tree that can be depended upon to cast dense shade in a parking lot, or to dependably line the street, and not be fussy about its surroundings, while taking smog and indifferent pruning for granted, then we can do a lot worse than plant the African sumac.

It is native to the central and Cape regions of South Africa, where it is called Karee and does especially well along stream banks. After initial planting in the Tucson area it was found to be very adaptable to most areas in the West. According to one report it actually started naturalizing in the Tucson area. We always become a little suspicious when trees do that, because we don’t want them to get out of hand in their new surroundings, but it is not listed as an invasive plant in California.

The evergreen African sumac grows at a slow to moderate rate to 20 to 30 feet tall and wide. It naturally assumes a graceful, open, spreading, multi-stem habit, reminiscent of an olive. Pruning of basal suckers will keep it a single trunk tree. On older trees fissures in the dark gray trunk reveal an orange color beneath. Young twigs are reddish in color. Leaves are divided into three willow-like, smooth-margined leaflets, 3 to 5 inches long, dark green but somewhat paler underneath. The tree drops some leaves in summer. Small whitish green flowers smell slightly sweet; pollen is allergenic; clusters of flowers on female trees develop into small pea-size fruit containing red or black seeds with papery coats. In its homeland the fruit was used to make beer. The tree loves full sun and is drought-resistant once established. It is not particular as to soil, but susceptible to Texas root rot.

The genus Rhus occurs worldwide. It is part of the Anacardiaceae family, which also houses such interesting members as mangoes, cashews and poison oak.

--Peter Severynen

Thoughts? Comments?