Accession Count: 12
Common Name:
African sumac
Family Name:
Anacardiaceae
Botanical Name:
Searsia lancea
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
Africa sumac is a tree reaching heights of 5-6 m (15 to 30 feet) with an equal or greater spread (1, 2, 3). It is grows slowly at a rate of ~ ¾ m (24 in) each year (1, 2). It is considered a small broadleaved, evergreen tree, with rounded canopy and upright form (3). While the canopy is very dense when young, it thins with age, and may also lose a lot of leaves especially during hot summers (1, 3). This tree is typically multi-trunked with many large scaffold limbs developing low on the trunk, and with many finer branches/branchlets higher in the canopy that have a slightly weeping habit. The bark is dark gray, deeply fissured, with an orange mahogany color beneath (1,2,3). Leaves are shiny, dark green, palmately compound, trifoliate (with 3 with leaflets), and arranged alternately on the stems (1, 2). The lower leaflets are linear-lanceolate in shape and 5-7 cm (2-3 inches) long while the terminal leaflet is larger: 12 cm × 1.5 cm (4.5-6 inches) (3). Leaf margins are usually entire, rarely serrate, and paler green to gray on the abaxial surface (3). The African sumac is dioecious having male and female plants (1, 4). The flowers appear in January and February, are inconspicuously small, white-yellow-green in color, and borne in terminal clusters as panicles (1, 2, 3, 4). Fruits are somewhat asymmetric spherical drupes, about 5 mm around, initially green or yellow incolor, becoming later red or brown (1, 2, 3). Each seed contained in the fruit is small, black, covered with a paper-like coating, and fully mature by June (1, 2).
Compound:
Sea lan
Geographic Origin:
South Africa
Ecozone Origin:
Afrotropic
Biome Origin:
Natural History:
Native to South Africa, where it is commonly known as Karee (1, 3). The species was renamed in the Integrated Taxonomic Information System (ITIS) and U.S National Plant Germplasm Repository System in the 2020s (1, 3). The accepted name of this plant is Searsia lancea (1, 3). The specific epithet "lancea" refers to the lance shaped leaves (1). In the american Southwest the tree is somewhat weedy/bordering on invasive as it produces a lot of seed and can also spread by suckering (3). On October 12, 1919, when Dr. Homer L. Shantz was associated with the Smithsonian Institution as an explorer, he collected propagating material of this species from Wonderboom, North Pretoria, Transvaal in South Africa on (4). He noted the beauty of the tree in its natural habitat, and recognized the potential for shade, timber, and animal feed (4). After propagating the tree, young trees were established at Chico, California, and two were transplanted to the Boyce Thompson Arboretum where Dr. F. J. Crider, a former University of Arizona horticulturist was serving as Director (4). When Dr. Shantz became President of the University in 1928, one of the trees from the Arboretum was moved to the University Campus just east of Maricopa Hall. Later, in 1941 two of these trees were planted in the lawn of the Library (now the Arizona State Museum). The species is now widely planted throughout Arizona, including in the 2020s, two of these trees were growing on the State Capitol grounds in Phoenix (4).
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Natural History of the UA Campus Arboretum Specimens:
Accession # 6712 was the first one of its kind planted in Tucson. The tree was grown from seed collected in North Pretoria, South Africa in 1919 by former President Homer Shantz. After germination in Chico, CA, two seedlings were transported to Arizona: one taken to Boyce Thompson SW Arboretum in Superior, AZ, and the other eventually planted on the UA campus in 1928. As a result of its history, it was recognized as a University Heritage Tree in 2003. This specimen was also designated a Great Tree of Arizona in 2003.
In 2018, accession # 3792 was measured and recognized as a state champion by the AZ Dept. of Forestry and Fire Management (5).
Cultivation Notes:
The African sumac is suited to USDA hardiness zone 9 (-1 to -6C or 20-30ºF) which classifies as semi-hardy for Tucson. However, twenty year old trees located at Sacaton, Arizona, survived a low temperature of 14 degrees F. in January, 1950 and mature trees on the University of Arizona campus experienced only minor damage in 2011 when temperatures dropped to 15F and did not go above freezing for 3 days (4). It is also very heat tolerant, classified for Sunset zones: 8 - 9, 12 - 24 The amount of water use for this species is low because it is required monthly. Water use is very low, it is adapted to full sun, and while it tolerates high summer temperatures, it may need some summer water in a the hottest months. (1. 2. 3) It prefers well-drained soil with loamy or sandy or clay texture(3, 4). It is reported to be adapted to slightly alkaline and very acid soils, with moderate tolerance to soil salinity and alkalinity (2, 3). Roots are generally not a problem for underground or surface infrastructure, biogenic emissions are low, and the trees are very to diseases (except Texas root rot and verticillium) and insects, though small branches, leaves and fruit produce litter (1, 2, 4).
Ethnobotany:
This plant is used primarily as a shade tree and an ornamental. It is quite popular on golf courses (1). Populations in Tucson were established in the mid-20th century and included trees planted by the Soil Conservation Nursery as a windbreak for ranchers (4).
Height:
20 - 50 feet
Width:
20 - 50 feet
Growth Rate:
Slow Growing
Grow Season:
Spring
Flower Season:
Winter
Color:
Green
Function:
Shade
Spread:
Spreading
Allergen:
Allergenic
Invasive:
Invasive
Toxicity:
Benign
Hardy:
Hardy
Water Use:
Low water Use
Citations:
1. Duffield, Mary Rose., and Warren D. Jones.
Plants For Dry Climates - How To Select, Grow And Enjoy. Lane Publishing Company, 1992.
