Pacific Island Ecosystems at Risk (PIER)


Searsia lancea


RISK ASSESSMENT RESULTS: High risk, score: 8


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments

Searsia lancea (Linneaus F.) F. A. Barkl. Family - Anacardiaceae. Common Names(s) - Karree, Willow rhus, African sumac. Synonym(s) - Rhus lancea L. f.

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

n

0

1.02

Has the species become naturalized where grown?

y=1, n=-1

1.03

Does the species have weedy races?

y= 1, n=-1

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

2

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

n

0

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

1

2.05

Does the species have a history of repeated introductions outside its natural range?

y=-2, ?=-1, n=0

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

2

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

n

0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

n

0

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

y

4

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

n

0

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

n

-1

4.05

Toxic to animals

y=1, n=0

n

0

4.06

Host for recognized pests and pathogens

y=1, n=0

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

y

1

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

y

1

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

y

1

4.11

Climbing or smothering growth habit

y=1, n=0

n

0

4.12

Forms dense thickets

y=1, n=0

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

n

0

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

n

-1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

-1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

3+

0

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

n

-1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

-1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

-1

7.05

Propagules water dispersed

y=1, n=-1

y

1

7.06

Propagules bird dispersed

y=1, n=-1

y

1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

-1

7.08

Propagules survive passage through the gut

y=1, n=-1

y

1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

n

-1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

8.03

Well controlled by herbicides

y=-1, n=1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

y

1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

8

Supporting data:

Notes

Source

1.01

(1)No evidence

(1)van Wyk, P. 2001. Southern African trees: a photographic guide. Struik, Cape Town, South Africa.

1.02

1.03

2.01

(1)It occurs in a belt which varies tremendously in width from northern Namibia, southwards to the western and southern Cape and then northwards through the Karoo and Orange Free State and the western half of the Transvaal into Zimbabwe and eastern Botswana.

(1)van Wyk, P. 2001. Southern African trees: a photographic guide. Struik, Cape Town, South Africa.

2.02

(1)It occurs in a belt which varies tremendously in width from northern Namibia, southwards to the western and southern Cape and then northwards through the Karoo and Orange Free State and the western half of the Transvaal into Zimbabwe and eastern Botswana.

(1)van Wyk, P. 2001. Southern African trees: a photographic guide. Struik, Cape Town, South Africa.

2.03

(1)In warm desert plantings, said to be hardy to 12°F. Occurs in Western Garden Zones 8-9 and 12-24, which includes most of the warm deserts of the southwestern U.S., except the Chihuahuan desert (Brexzel 2001). (2)One drawback of what seems to be an indestructible little tree is its lack of cold hardiness. Temperatures below 15 degrees F (-9.5 degrees C) for any length of time frost back the twigs, and, only a few degrees colder, the top can be entirely lost. If the tree form is not important, and it is to be grown only for the graceful leaves, Rhus lancea has proven root hardy through fairly long periods (a few days) of lows below 10 degrees F (-12 degrees C), regaining several feet of new growth the following season. (3)Hardiness: USDA Zone 8b: to -9.4 °C (15 °F) USDA Zone 9a: to -6.6 °C (20 °F) USDA Zone 9b: to -3.8 °C (25 °F) USDA Zone 10a: to -1.1 °C (30 °F) USDA Zone 10b: to 1.7 °C (35 °F) (4)USDA Hardiness Zone: 7 to 10

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (2)Hogan, S. 2008. Trees for All Seasons: Broadleaved Evergreens for Temperate Climates. Timber Press, Portland, OR. (3)http://davesgarden.com/guides/pf/go/81521/ [Accessed 12 Oct 2009] (4)http://www.backyardgardener.com/plantname/pd_17bc.html [Accessed 13 Oct 2009]

2.04

(1)It occurs in a belt which varies tremendously in width from northern Namibia, southwards to the western and southern Cape and then northwards through the Karoo and Orange Free State and the western half of the Transvaal into Zimbabwe and eastern Botswana.

(1)van Wyk, P. 2001. Southern African trees: a photographic guide. Struik, Cape Town, South Africa.

2.05

(1)Not known if African sumac is invasive in these states, but it is present in California, Nevada, New Mexico, and Texas (Duffield and Jones 2003). (2)This plant has been said to grow in the following regions: Phoenix, Arizona Sun City, Arizona Tucson, Arizona (2 reports) Brentwood, California Temecula, California Las Vegas, Nevada (2 reports) San Antonio, Texas

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (2)http://davesgarden.com/guides/pf/go/81521/ [Accessed 12 Oct 2009]

3.01

(1)"the species has probably become naturalized in Riverside County, and in Arizona the species is considered an escapee from cultivation (Rondeau et al. 1999) and an invasive weed (Campbell 1999). (2)Rhus lancea L.f. is a fairly large evergreen tree with a broad, spreading top, which has become naturalized in the Southwest.

(1)Austin, A. and M. Dowton. 2000. Hymenoptera: evolution, biodiversity and biological control. CSIRO Publishing, Collingwood, Australia. (2)Carr, M. E., C. T Mason Jr., and M. O. Bagby. 1986. Renewable Resources from Arizona Trees and Shrubs. Forest Ecology and Management, 16: 155-167.

3.02

(1)See 3.04

(1)http://www.hear.org/gcw/species/rhus_lancea/ [Accessed 13 Oct 2009]

3.03

(1)Listed as an agricultural weed, but no evidence of impacts or control measures given

(1)Wells, M.J., Balsinhas, V.M., Joffe, H., Engelbrecht, V.M., Harding, G. and Stirton, C.H. (1986) A Catalogue of Problem Plants in Southern Africa, incorporating The National Weed List of South Africa. Memoirs of the Botanical Survey of South Africa No. 53. Botanical Research Institute, Pretoria, South Africa.

3.04

(1)Invades desert washes (Brock and Farkas 1997, Tellman 2002; P. Jenkins, personal communication, 2005) in which its physical presence could divert channel flows during times of peak storm flow (Stromberg 2001). Presence in channel may also enhance potentials for streambank erosion by directing water with more force into the bank...Through shading and physical presence, African sumac plants can restrict understory vegetation...African sumac was the second most invasive plant, after Bermudagrass (Cynodon dactylon), in a “plants-out-of-place” survey conducted as a field laboratory on the Arizona State University, Tempe Campus, by students in a landscape architecture course (PLA 240) in the fall of 2003 (J. Brock, personal observations, 2004). African sumac is now commonly seen growing with other horticultural plantings in urban areas indicating a high reproductive potential. See Worksheet A. (2)An arid-land tree of South Africa, Rhus lancea was originally imported into the U.S. by the landscape industry and was introduced to Tucson in the 1920s by a UA botanist. Its pollens disperse from November to February and are highly allergenic. Female trees produce large quantities of seeds, which are distributed by the birds who eat them.Once established along a wash or roadside, it spreads quickly, and since its canopy produces very deep shade it tends to crowd out native species. Since its root system is invasive and deep, the plant is hard to remove, and has now become a common weed in Pima County urban areas (though not yet in our SJ area). Click on Rhus and Rhus-2 for detailed images. (3)Rhus lancea INVASIVE WEED A widely promoted low water use landscape tree that threatens riparian areas by diverting channel flow, thus enhancing the potential for streambank erosion, and it can displace mesquites. Besides producing abundant seeds, it also spreads by suckers and competes with native plants for water. (4)re-seeds easily and naturalizes in urban landscapes and riparian areas

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (2)http://www.saguaro-juniper.com/i_and_i/invasive_spp/invasive_plants.html [Accessed 12 Oct 2009] (3)http://www.buffelgrass.org/pdf/GrowNative.pdf [Accessed 12 Oct 2009] (4)Chambers, N., and T. Oshant Hawkins. 2002. Invasive Plants of the Sonoran Desert: A Field Guide. Sonoran Institute, Environmental Education Exchange, and National Fish and Wildlife Foundation.

3.05

(1)No evidence [although several members of this species former genus Rhus are invasive]

(1)http://www.hear.org/gcw/scientificnames/scinames.htm [Accessed 12 Oct 2009]

4.01

(1)It is usually a single-stemmed, low branching tree which has a dense, soft, round canopy. The karee has a course textured bark and on older specimens it is dark grey or brown in colour while on young branches and trees it is a reddish brown-colour. The leaves are trifoliate (a compound leaf with three leaflets), possessing narrowly lanceolate (lance shaped) leaflets. The leaves are dark green above and paler green below. They do not have any hairs on them and the margins of the leaves are entire. The leaves are leathery and are often sickle shaped. [no evidence]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.02

(1)Although African sumac could supply a canopy micro-site for annuals, some biologists believe the plant may produce allelopathic materials to neighboring plants (P. Jenkins, personal communication, 2005). Allelopathy is always difficult to substantiate and separate from direct competition. The result in any event would be lowered community diversity. May replace mesquite and paloverde in the desert landscape, but this would not change the physical structure of the plant community. [suspected of allelopathy, but see reference 2] (2)Searsia lancea does not have an aggressive root system and can be used near paving and tarred surfaces. Because the karee is hardy, frost resistant and evergreen, it is ideal for establishing a protective canopy for frost sensitive and shade loving plants. It could thus be considered as a possible pioneer plant for establishing a new forest in an area that receives frost. [use as nurse plants suggests tree is not allelopathic, contrary to reference 1] (3)thought to be allelopathic and inhibits the growth of other plants in its area (4)Mechanical control: Individual plants should be removed by shovel or digging bar immediately. Larger plants should be removed by bulldozer. This species needs to be hauled off-site, even if there are no seeds, because it is allelopathic.

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009] (3)Chambers, N., and T. Oshant Hawkins. 2002. Invasive Plants of the Sonoran Desert: A Field Guide. Sonoran Institute, Environmental Education Exchange, and National Fish and Wildlife Foundation. (4)http://rfcd.pima.gov/projects/rillitoswan/pdfs/workplan.pdf [Accessed 13 Oct 2009]

4.03

(1)It is usually a single-stemmed, low branching tree which has a dense, soft, round canopy. The karee has a course textured bark and on older specimens it is dark grey or brown in colour while on young branches and trees it is a reddish brown-colour. The leaves are trifoliate (a compound leaf with three leaflets), possessing narrowly lanceolate (lance shaped) leaflets. The leaves are dark green above and paler green below. They do not have any hairs on them and the margins of the leaves are entire. The leaves are leathery and are often sickle shaped. [no evidence]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.04

(1)The leaves of R. lancea are used as a valuable fodder for livestock and are believed to taint the flavor of milk if eaten in large quantities by diary cattle. (2)Game animals such as kudu, roan antelope and sable browse the leaves of the tree which can serve as an important food source for them in times of drought.

(1)Venter, F. and J. Venter. 1996. Making the Most of Indigenous Trees. 1st edition. Pretoria. Briza Publications. (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.05

(1)The leaves of R. lancea are used as a valuable fodder for livestock and are believed to taint the flavor of milk if eaten in large quantities by diary cattle. (2)Game animals such as kudu, roan antelope and sable browse the leaves of the tree which can serve as an important food source for them in times of drought.

(1)Venter, F. and J. Venter. 1996. Making the Most of Indigenous Trees. 1st edition. Pretoria. Briza Publications. (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.06

(1)Susceptible to Texas root rot (2)Some trees in the central highlands seem to be affected by a disease that causes leaves at the extremities of the young branches to become entirely deformed. (3)Muribasidiospora indica was identified as the causal organism associated with leaf spots of Rhus lancea in South Africa. The disease appears more commonly in the warmer provinces of South Africa (Gauteng, Free State) than in the Western Cape. The morphological identification of the causal organism was confirmed by comparing sequence data of the large subunit rRNA gene (28S) with that of reference strains of M. indica. This is the first confirmed record of this species occurring in Africa, where it appears to be a serious leaf pathogen on members of the Anacardiaceae. [potential pest of mango trees and native Rhus sandwicensis]

(1)http://ag.arizona.edu/pima/gardening/aridplants/Rhus_lancea.html [Accessed 12 oct 2009] (2)http://www.biodiversity.org.na/treeatlas/SpPDFs/Sp487.pdf [Accessed 12 Oct 2009] (3)Crous, P. W., J. Z. Groenewald and G. Carroll. 2003. Muribasidiospora indica causing a prominent leaf spot diseaseon Rhus lancea in South Africa. Australasian Plant Pathology 32(2) 313 - 316

4.07

(1)"Pollen of African sumac is highly allergenic to some individuals and perhaps to other mammals" (2)pollen is allergenic

(1)Chambers, N., and T. Oshant Hawkins. 2002. Invasive Plants of the Sonoran Desert: A Field Guide. Sonoran Institute, Environmental Education Exchange, and National Fish and Wildlife Foundation. (2)http://ag.arizona.edu/pima/gardening/aridplants/Rhus_lancea.html [Accessed 12 Oct 2009]

4.08

(1)"In contrast, many woody fuels are also volatile fuels high in fats, resins and volatile oils, which often produce enough firebrands to create great danger of igniting fuels a distance ahead of the fire. Examples of volatile woody fuels are Euclea crisp, Rhus lancea and Vitex rehmannii.

(1)Goldammer, J. G. 2004. Wildland fire management handbook for Sub-Sahara Africa. Blue Weaver Marketing, Cape Town, South Africa.

4.09

(1)Exposure: full sun, reflected sun, part shade (2)Sun Exposure: Full Sun Sun to Partial Shade (3)requires full sun to partial shade

(1)http://ag.arizona.edu/pima/gardening/aridplants/Rhus_lancea.html [Accessed 12 oct 2009] (2)http://davesgarden.com/guides/pf/go/81521/ [Accessed 12 Oct 2009] (3)Chambers, N., and T. Oshant Hawkins. 2002. Invasive Plants of the Sonoran Desert: A Field Guide. Sonoran Institute, Environmental Education Exchange, and National Fish and Wildlife Foundation.

4.10

(1)It tolerates a wide range of soil and moisture conditions but needs good drainage. (2)The karee can adapt well to different soils including those that are poorly drained (which means that it can be planted almost anywhere).

(1)Carr, M. E., C. T Mason Jr., and M. O. Bagby. 1986. Renewable Resources from Arizona Trees and Shrubs. Forest Ecology and Management, 16: 155-167. (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.11

(1)The karee is a small to medium sized evergreen tree that usually grows to a height of 7 m and a width of 7 m but can be larger depending on environmental factors.

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

4.12

(1)Once established along a wash or roadside, it spreads quickly, and since its canopy produces very deep shade it tends to crowd out native species. [potentially forming dense thickets]

(1)http://www.saguaro-juniper.com/i_and_i/invasive_spp/invasive_plants.html [Accessed 13 Oct 2009]

5.01

(1)Terrestrial

(1)Chambers, N., and T. Oshant Hawkins. 2002. Invasive Plants of the Sonoran Desert: A Field Guide. Sonoran Institute, Environmental Education Exchange, and National Fish and Wildlife Foundation.

5.02

(1)Most of the species grown in southern Africa, belonging to the genus Rhus, have been placed in Searsia. In southern Africa there are about 111 species of Searsia. Searsia lancea belongs to the family Anacardiaceae (the Mango family) which is the fourth largest tree family in southern Africa.

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

5.03

(1)Most of the species grown in southern Africa, belonging to the genus Rhus, have been placed in Searsia. In southern Africa there are about 111 species of Searsia. Searsia lancea belongs to the family Anacardiaceae (the Mango family) which is the fourth largest tree family in southern Africa.

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

5.04

(1)It is usually a single-stemmed, low branching tree which has a dense, soft, round canopy. The karee has a course textured bark and on older specimens it is dark grey or brown in colour while on young branches and trees it is a reddish brown-colour. The leaves are trifoliate (a compound leaf with three leaflets), possessing narrowly lanceolate (lance shaped) leaflets. The leaves are dark green above and paler green below. They do not have any hairs on them and the margins of the leaves are entire. The leaves are leathery and are often sickle shaped. [no evidence]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

6.01

(1)Searsia lancea can be propagated easily from seed, cuttings or layers. The ripe seed should be sown in seedling trays using a good seedling medium and transplanted into bigger containers when the seedlings reach the two leaf stage. [no evidence]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

6.02

(1)Searsia lancea can be propagated easily from seed, cuttings or layers. The ripe seed should be sown in seedling trays using a good seedling medium and transplanted into bigger containers when the seedlings reach the two leaf stage.

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

6.03

Unknown

6.04

(1)The male and female trees are separate.

(1)Pienaar, K. 1991. Gardening with Indigenous Plants: Easy to Grow Southern African Plants. Struik Publishing, Cape Town, SA.

6.05

(1)The small, inconspicuous flowers are presented as much-branched sprays which are greenish-yellow in colour and are produced from June until September…The sweetly scented flowers attract bees and other insects to them. [no evidence, and flowers unspecialized]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

6.06

(1)Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes: No...Fragments easily and fragments can become established elsewhere: "No"

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

6.07

(1)Growth rate is fast when young, and the species appears to be very adaptable to pollarding. (2)The tree can grow up to 80 cm a year and is thus fairly fast growing. (3)Reaches reproductive maturity in 2 years or less: No

(1)Carr, M. E., C. T Mason Jr., and M. O. Bagby. 1986. Renewable Resources from Arizona Trees and Shrubs. Forest Ecology and Management, 16: 155-167. (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009] (3)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

7.01

(1)The small, inconspicuous flowers are presented as much-branched sprays which are greenish-yellow in colour and are produced from June until September. The male and female flowers occur on separate trees. The fruit are small (up to 5mm in diameter), round, slightly flattened and covered with a thin fleshy layer which is glossy and yellowish to brown when ripe. [no evidence, and no means of external attachment]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

7.02

(1)Humans began planting African sumac in Arizona in the late 1920s. Humans have continued to spread this tree by direct planting...Humans continue to plant this species in landscape/horticultural settings (Pima County Board of Supervisors 2002, Duffield and Jones 2003). (2)The leaves of the karee provide valuable fodder for livestock but can taint the flavour of milk if eaten in large quantities by dairy cattle as a result of the resin contained in them. The tree is also an important source of shade for livestock in certain regions. The bark, twigs and leaves provide tannin. In the past the hard wood was used for fence posts, tool handles and parts of wagons. Bowls, tobacco pipes and bows were also made from the wood. The fruits are edible and were once used as an important ingredient of mead or honey beer. The word karee is said to be the original Khoi word for mead...Searsia lancea is therefore ideally suited for use as a street tree. Aesthetically the karee is a graceful tree possessing a willow-like appearance due to its drooping habit and this makes it suitable for use near water e.g. next to a water garden, dam or river.

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (2)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

7.03

(1)The small, inconspicuous flowers are presented as much-branched sprays which are greenish-yellow in colour and are produced from June until September. The male and female flowers occur on separate trees. The fruit are small (up to 5mm in diameter), round, slightly flattened and covered with a thin fleshy layer which is glossy and yellowish to brown when ripe. [no evidence of being grown with other produce]

(1)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

7.04

(1)It is also spreading naturally through the action of birds, since seedlings are observed under nest or perching sites, and establishing without human action along stream channels (Tellman 2002; J. Brock, personal observations, 2004 and P. Jenkins, personal communication, 2005). For example, it has been found several miles from residential areas along Skunk Creek in Maricopa County and is observed to be moving along washes in Pima County...Is spreading from urbanized/human settlements into desert habitats, especially along streams/washes and arroyos (Baker 1997). Spread is estimated to be 0.5 mile per year (J. Brock, personal observations, 2004). Phil Jenkins (personal communication, 2005) has observed that in 10 years this species has spread from the Tucson urban area into the Tucson Mountains and Saguaro National Park...Birds relish the fruit of African sumac and excrete the seeds under roost trees or perching sites, as seedlings of this species often are found under established trees (J. Brock, personal observations, 2004). Seeds are dispersed primarily by birds and with flood flows in invaded channels. Fruit/seeds are a food source for birds and perhaps small mammals that subsequently can disperse the seeds to new locales (J. Brock, personal observations, 2004)

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

7.05

(1)It is also spreading naturally through the action of birds, since seedlings are observed under nest or perching sites, and establishing without human action along stream channels (Tellman 2002; J. Brock, personal observations, 2004 and P. Jenkins, personal communication, 2005). For example, it has been found several miles from residential areas along Skunk Creek in Maricopa County and is observed to be moving along washes in Pima County...Is spreading from urbanized/human settlements into desert habitats, especially along streams/washes and arroyos (Baker 1997). Spread is estimated to be 0.5 mile per year (J. Brock, personal observations, 2004). Phil Jenkins (personal communication, 2005) has observed that in 10 years this species has spread from the Tucson urban area into the Tucson Mountains and Saguaro National Park...Birds relish the fruit of African sumac and excrete the seeds under roost trees or perching sites, as seedlings of this species often are found under established trees (J. Brock, personal observations, 2004). Seeds are dispersed primarily by birds and with flood flows in invaded channels. Fruit/seeds are a food source for birds and perhaps small mammals that subsequently can disperse the seeds to new locales (J. Brock, personal observations, 2004)

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

7.06

(1)The fruit is small, kidney-shaped, yellowish brown and eaten by birds. (2)"An abundance of seeds that are used by birds for seed and perhaps javelina in wildland or urban fringe settings. Pollen of African sumac is highly allergenic to some individuals (Chambers and Hawkins 2002) and perhaps to other mammals"..Birds relish the fruit of African sumac and excrete the seeds under roost trees or perching sites, as seedlings of this species often are found under established trees (J. Brock, personal observations, 2004). Seeds are dispersed primarily by birds and with flood flows in invaded channels. Fruit/seeds are a food source for birds and perhaps small mammals that subsequently can disperse the seeds to new locales (J. Brock, personal observations, 2004) (3)The fruit is eaten by birds such as bulbuls, guineafowl and francolins.

(1)Pienaar, K. 1991. Gardening with Indigenous Plants: Easy to Grow Southern African Plants. Struik Publishing, Cape Town, SA. (2)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (3)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

7.07

(1)The fruit is small, kidney-shaped, yellowish brown and eaten by birds. (2)"An abundance of seeds that are used by birds for seed and perhaps javelina in wildland or urban fringe settings. Pollen of African sumac is highly allergenic to some individuals (Chambers and Hawkins 2002) and perhaps to other mammals"..Birds relish the fruit of African sumac and excrete the seeds under roost trees or perching sites, as seedlings of this species often are found under established trees (J. Brock, personal observations, 2004). Seeds are dispersed primarily by birds and with flood flows in invaded channels. Fruit/seeds are a food source for birds and perhaps small mammals that subsequently can disperse the seeds to new locales (J. Brock, personal observations, 2004) (3)The fruit is eaten by birds such as bulbuls, guineafowl and francolins.

(1)Pienaar, K. 1991. Gardening with Indigenous Plants: Easy to Grow Southern African Plants. Struik Publishing, Cape Town, SA. (2)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009] (3)http://www.plantzafrica.com/plantqrs/searsialancea.htm [Accessed 12 Oct 2009]

7.08

(1)The fruit is small, kidney-shaped, yellowish brown and eaten by birds.

(1)Pienaar, K. 1991. Gardening with Indigenous Plants: Easy to Grow Southern African Plants. Struik Publishing, Cape Town, SA.

8.01

(1)Relatively prolific seed producer and sprouts from basal stems and roots...Dense infestations produce >1,000 viable seed per square meter [answered "No"]

(1)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

8.02

(1)Storage Behaviour: Orthodox? [longevity of soil seed bank under field conditions unknown]

(1)Liu, K., Eastwood, R.J., Flynn, S., Turner, R.M., and Stuppy, W.H. 2008. Seed Information Database (release 7.1, May 2008) http://www.kew.org/data/sid

8.03

(1)Herbicidal control: There is very little information on herbicides that would be effective for control of African sumac. Various broadleaf herbicides may need to be tried to find the best one.

(1)Fenner, P. 2007. Environmental Assessment. Integrated Treatment of Noxious or Invasive Plants.

8.04

(1)Growth rate is fast when young, and the species appears to be very adaptable to pollarding. (2)Relatively prolific seed producer and sprouts from basal stems and roots...Resprouts readily when cut, grazed, or burned: "Yes"

(1)Carr, M. E., C. T Mason Jr., and M. O. Bagby. 1986. Renewable Resources from Arizona Trees and Shrubs. Forest Ecology and Management, 16: 155-167. (2)http://sbsc.wr.usgs.gov/research/projects/swepic/SWVMA/PLANTPDF/Rhus_lancea_AZ_PAF.pdf [Accessed 09 Oct 2009]

8.05

(1)Biological control: There are no available biocontrol agents for African sumac.

 

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