Tree spurge (Euphorbia dendroides)

Present distribution

Scientific name:	Euphorbia dendroides L.
Common name(s):	tree spurge

Map showing the present distribution of this weed.

Habitat:

Native to northern Africa, Turkey and southern Europe (GRIN 2010). Naturalised in Victoria, South Australia and Western Australia (Groves et al.
2003). Invaded abandoned farmland at low altitudes in Italy (Piussi 2007); grows in thermophilous [high temperatures] scrubland (Traveset & Saez
1997). Belongs to the Subsection Pachycladae of the Subgenus Esula, of which all species “would appear…adapted for coastal habitats” (Hassall
1977). “Distributed along the coastline of the countries surrounding the Mediterranean, in rocky thermophilous enclaves, no higher than 400 m”
(Molero et al. 2002).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:

Ecological Vegetation Divisions
Coastal; rocky outcrop shrubland; semi-arid woodland; chenopod shrubland; chenopod mallee; hummock-grass mallee; lowan mallee; broombush whipstick

Colours indicate possibility of Euphorbia dendroides infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map showing the potential distribution of euphorbia dendroides

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Single-stemmed deciduous shrub up to 2 m in height (Traveset and Saez 1997). A photograph of an infestation being removed shows a tractor cutting through the infestation (Wildscape Restoration 2010), without which, access appears impossible. Significant works required to provide reasonable access.	H	M
2. Reduce tourism?	Observed growing along a stream in San Gabriel Mountains Angeles National forest (University of California 2010). With an ability to form infestations 2 m high (Wildscape Restoration 2010) this species may restrict access to waterways, affecting some recreational pursuits.	MH	M
3. Injurious to people?	Toxic (Groves et al. 2003). Recorded as having caused an eye injury (Wagstaff 2008). Mildly toxic, may cause some physiological issues.	ML	MH
4. Damage to cultural sites?	Single-stemmed deciduous shrub up to 2 m in height (Traveset and Saez 1997). May have a moderate visual effect.	ML	M
Abiotic
5. Impact flow?	No record of this species growing in aquatic environments.	L	MH
6. Impact water quality?	Summer deciduous (Barboni et al. 2004). Observed growing along a stream in San Gabriel Mountains Angeles National forest (University of California 2010). With an ability to form infestations 2 m high (Wildscape Restoration 2010) this species may contribute nutrient loads to waterways and cause moderate but noticeable effects in both dissolved O₂ and light causing increased algal growth.	MH	ML
7. Increase soil erosion?	Lives for 40 years (Margaris & Vokou 1983). Unlikely to leave soil open to erosion.	L	M
8. Reduce biomass?	Unknown.	M	L
9. Change fire regime?	Unknown.	M	L
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Dry Creekline Woodland (E); CMA = Wimmera; Bioregion = Greater Grampians; VH CLIMATE potential. Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	L	M
(b) medium value EVC	EVC = Coastal Headland Scrub (D); CMA = West Gippsland; Bioregion = Gippsland Plain; VH CLIMATE potential. Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	L	M
(c) low value EVC	EVC = Sandstone Ridge Shrubland (LC); CMA = Mallee; Bioregion = Lowan Mallee; VH CLIMATE potential. Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	L	M
11. Impact on structure?	Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	L	M
12. Effect on threatened flora?	Unknown.	MH	L
Fauna
13. Effect on threatened fauna?	Unknown.	MH	L
14. Effect on non-threatened fauna?	Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	L	M
15. Benefits fauna?	Naturalised in Australia but not considered important enough to warrant control at any location (Groves et al. 2003). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). Appears to only invade disturbed areas. No further impact on natural ecosystems evident.	H	M
16. Injurious to fauna?	Evidence for herbivory was only found as applies to nectar and seeds (Traveset & Saez 1997). Toxic (Groves et al. 2003). Crushed stems stun fish and said to irritate their eyes (Brussell 2004). “Grazing animals are…capable of…selecting the more appetizable [sic] species…rather than the toxic (Euphorbia dendroides) (Camarda et al. 2008). Evidence suggests that negative impacts on animals require human intention.	L	M
Pest Animal
17. Food source to pests?	Evidence for herbivory was only found as applies to nectar and seeds (Traveset & Saez 1997). Crushed stems stun fish and said to irritate their eyes (Brussell 2004). “Grazing animals are…capable of…selecting the more appetizable [sic] species…rather than the toxic (Euphorbia dendroides) (Camarda et al. 2008). May provide food source to minor pests.	ML	M
18. Provides harbour?	Single-stemmed deciduous shrub up to 2 m in height (Traveset and Saez 1997). A photograph of an infestation being removed shows a tractor cutting through what appears to be an infestation at least several metres square (Wildscape Restoration 2010). May provide harbour for minor pest species.	ML	M
Agriculture
19. Impact yield?	Present in Victoria, South Australia and Western Australia, but not rated as an agricultural weed either because it was not considered a problem or because it was not known to occur in agricultural areas (Groves et al. 2003). Toxic (Groves et al. 2003) but only reference to agricultural land is of this species invading abandoned farmland (Piussi 2007), rather than occurring as an agricultural weed. Unlikely to impact yield.	L	M
20. Impact quality?	Present in Victoria, South Australia and Western Australia, but not rated as an agricultural weed either because it was not considered a problem or because it was not known to occur in agricultural areas (Groves et al. 2003). Toxic (Groves et al. 2003) but only reference to agricultural land is of this species invading abandoned farmland (Piussi 2007), rather than occurring as an agricultural weed. Unlikely to impact quality.	L	M
21. Affect land value?	Present in Victoria, South Australia and Western Australia, but not rated as an agricultural weed either because it was not considered a problem or because it was not known to occur in agricultural areas (Groves et al. 2003). Toxic (Groves et al. 2003) but only reference to agricultural land is of this species invading abandoned farmland (Piussi 2007), rather than occurring as an agricultural weed. Unlikely to affect land value	L	M
22. Change land use?	Present in Victoria, South Australia and Western Australia, but not rated as an agricultural weed either because it was not considered a problem or because it was not known to occur in agricultural areas (Groves et al. 2003). Toxic (Groves et al. 2003) but only reference to agricultural land is of this species invading abandoned farmland (Piussi 2007), rather than occurring as an agricultural weed. Unlikely to change land value.	L	M
23. Increase harvest costs?	Present in Victoria, South Australia and Western Australia, but not rated as an agricultural weed either because it was not considered a problem or because it was not known to occur in agricultural areas (Groves et al. 2003). Toxic (Groves et al. 2003) but only reference to agricultural land is of this species invading abandoned farmland (Piussi 2007), rather than occurring as an agricultural weed. Unlikely to increase harvest costs.	L	M
24. Disease host/vector?	Alternative host for whitefly (Calvitti & Remotti 1998); a common pest of horticultural crops.	M	H

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Seeds germinate following fire in one study (Camarda et al. 2008). Generic instructions for growing Euphorbia suggests to sow seed “in any well drained, rather sandy or rocky soil at a minimum of some 15°C all year long.” (www.rareplants.de 2010). As long as the minimum temperature is achieved, it appears that this species may germinate at any time of the year.	H	ML
2. Establishment requirements?	Generic instructions for growing Euphorbia suggests to sow seed and “keep pots in a sunny spot” (www.rareplants.de 2010). This species is often found in open areas (see Molero et al. 2002; Richardson et al. 2006; Piussi 2007), however the ability to grow in scrubland (Traveset & Saez 1997) suggests that this species may establish under some canopy cover.	MH	M
3. How much disturbance is required?	Found “distributed along the coastline of the countries surrounding the Mediterranean, in rocky thermophilous [high temperature] enclaves, no higher than 400 m” (Molero et al. 2002) and scrubland (Traveset & Saez 1997). Occasionally escapes from gardens to persist in disturbed sites (Richardson et al. 2006) and has invaded abandoned farmland at low altitudes in Italy (Piussi 2007). The open and/or disturbed nature of these habitats suggests that the species establishes in highly disturbed ecosystems.	ML	M
Growth/Competitive
4. Life form?	Deciduous shrub (Travest & Saez 1997).	L	H
5. Allelopathic properties?	Whilst E. esula from the same subgenus (Hassall 1977) has some allelopathic properties, no evidence was found for allelopathy in this species, although evidence to the contrary was also not found.	M	L
6. Tolerates herb pressure?	Evidence for herbivory was only found as applies to nectar and seeds (Traveset & Saez 1997). Evidence for use of this species as a laxative (Grieve 2010) and toxic properties (Groves et al. 2003; Brussell 2004) suggest that this plant would be not eaten by animals. “Grazing animals are…capable of…selecting the more appetizable [sic] species…rather than the toxic (Euphorbia dendroides) (Camarda et al. 2008). Favoured by heavy grazing pressure as not eaten by animals/insects.	H	M
7. Normal growth rate?	Unknown.	M	L
8. Stress tolerance to frost, drought, w/logg, sal. etc?	‘Euphorbia dendroides is a master at coping with drought’ (Gildemeister 2003) and is summer-deciduous (Barboni et al. 2004). Destroyed by fire in one study (Camarda et al. 2008). Belongs to the Subsection Pachycladae of the Subgenus Esula, of which all species “would appear…adapted for coastal habitats” (Hassall 1977). Semi-hardy (www.rareplants.de 2010). Habitats where this species is found, including rocky enclaves (Molero et al. 2002) and a beach and gravel reserve (ALA 2010) suggest that this species does not tolerate waterlogging. Highly tolerant of drought and salinity, some tolerance of frost, not tolerant of fire and likely not waterlogging.	MH	MH
Reproduction
9. Reproductive system	Self-compatible but with no autogamy (Travest & Saez 1997). No evidence of vegetative reproduction but it does occur in the genus (Rodd 2001). Unknown if this species reproduces only by sexual means (self and cross pollination) or if it can reproduce vegetatively as well.	M	L
10. Number of propagules produced?	Each adult plant produces hundreds of thousands of inflorescences, with an average seed set of 1.8 viable seeds per inflorescence (Travest & Saez 1997). 100 000 x 1.8 = 180 000 seeds per plant.	H	H
11. Propagule longevity?	Seeds germinate very irregularly over a longer period, some may germinate within one week after potting, and others may need up to six months (www.rareplants.de 2010). Soil seed bank described as transient in one study (Crosti & Piotto 2006). Likely most seeds last less than 5 years.	L	MH
12. Reproductive period?	Reaches an a age of 40 years (Margaris & Vokou 1983). Likely to produce viable propagules for at least 10 years.	H	M
13. Time to reproductive maturity?	Unknown.	M	L
Dispersal
14. Number of mechanisms?	Unknown.	M	L
15. How far do they disperse?	Unknown.	M	L

References

Barboni D, Harrison SP, Bartlein PJ, Jalut G, New M, Prentice IC, Sanchez-Goni M-F, Spessa A, Davis B, and Stevenson AC. (2004) “Relationships Between Plant Traits and Climate in the Mediterranean Region: A Pollen Data Analysis.” In: Journal of Vegetation Science. 15: 635-646.

Brussell DE. “Medicinal Plants of Mt Pelion Greece.” In: Economic Botany (Supplement). 58 S174-S202.

Calflora. (2010 Available at http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=8558 (verified 02 June 2010).

Calvitti M. and Remotti PC. (1998) Host Preference and Performance of Bemisia argentifolii (Homoptera: Aleyrodidae) on Weeds in Central Italy.” In: Environmental entomology, 27(6): 1350-1356.

Camarda I, Brundu G, and Satta V. (2008) “Fire in Mediterranean Macchia: a Case of Study in Southwest Sardinia.” In: Gonzalez-Caban A. (Technical Coordinator) Proceedings of the Second International Symposium on Fire Economics, Planning and Policy: A Global View. USDA Forest Service, Albany, California.

Crosti R, and Piotto B. (2006) “Soil Seed Bank Restoration: The Role of Post-Fire Enhancing Agents, Such As Smoke, in Germination of Mediterranean Native Species.” In: 16th Meeting of the Italian Society of Ecology Viterbo Civitavecchia. (Eds.). Viewed at http://www.ecologia.it/congressi/XVI/articles/crosti-70.pdf (verified 02 June 2010).

Gildemeister H. (2003) Mediterranean Gardening: A Waterwise approach. http://books.google.com.au/books?id=0e56Sedc_YsC&pg=PA22&dq=euphorbia+dendroides&cd=1#v=onepage&q=euphorbia%20dendroides&f=false (verified 02 June 2010).

Gonzalez-Caban A. (Technical Coordinator) (2008) Proceedings of the Second International Symposium on Fire Economics, Planning, and Policy: A Global View. USDA Forest Service, Albany, USA.

Groves RH (Convener), Hosking JR, Batianoff GN, Cooke, D.A. Cowie ID, Johnson RW, Keighery GJ, Lepschi BJ, Mitchell AA, Moerkerk M, Randall RP, Rozefelds AC, Walsh NG and Waterhouse BM. (2003) Weed Categories for Natural and Agricultural Ecosystem Management. Bureau of Rural Sciences, Canberra.

Hassall DC. (1977) The Genus Euphorbia in Australia. Australian Journal of Botany. 25: 429-53.

HEAR. (2007) Available at http://www.hear.org/gcw/species/euphorbia_dendroides/ (verified 02 June 2010).

Malta Wild Plants. (2008) Available at http://www.maltawildplants.com/EUPH/Euphorbia_dendroides.php (verified 02 June 2010).

Margaris NS, and Vokou D. (1983) “Quality and Quantity of Latex which can be Produced From Natural Vegetation in Greece.” In: Palz W, and Pirrwitz D. (Eds.). Energy from biomass: proceedings of the Workshop and EC Contractors’ Meeting Held in Capri 7-8 June, 1983. Reidel Publishing, Holland.

Molero J, Garnatje T, Rovira A, Garcia-Jacua N, and Susanna A. (2002) “Karyological Evolution and Molecular Phylogeny in Macaronesian Dendroid Spurges (Euphorbia subsect. Pachycladae).” In: Plant Systematics and Evolution. 231: 109-132.

Paczkowska G. (1996). FloraBase: Flora of Western Australia. Available at http://florabase.calm.wa.gov.au/browse/profile/4624 (verified 02 June 2010).

Piussi P. (2007) Spontaneous Afforestation of Fallows in Italy. Available at www.boku.ac.at/zib/ippiussi2.htm (verified 02 June 2010).

Rare Plants. (2010) Available at www.rareplants.de (verified 02 June 2010).

Richardson FJ, Richardson RG and Shepherd RCH. (2006) Weeds of the South-east. An Identification Guide for Australia. RG & FJ Richardson, Meredith.

Traveset A (1995) “Spatiotemporal Variation in Pre-dispersal Reproductive Losses of Mediterranean, Euphorbia dendroides L.” In: Oecologica 103: 118-126. Available at http://www.springerlink.com/content/g486161118mkl162/ (verified 02 June 2010).

Traveset A and Saez E. (1997) “Pollination of Euphorbia dendroides by Lizards and Insects: Spatio-Temporal Variation in Patterns of Flower Visitation.” In: Oecologica 111: 241- 248. Available online at http://www.jstor.org/pss/4221685 (verified 02 June 2010).

United States Department of Agriculture. Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). (2010) Euphorbia dendroides. Available at www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?16363 (verified 02 June 2010).

University of California. (2010) Consortium of California Herbaria Available at http://ucjeps.berkeley.edu/consortium (verified 02 June 2010).

Wagstaff DJ. (2008) International Poisonous Plants Checklist: an Evidence-based Reference. CRC Press, USA.

Walsh N and Stajsic V. (2007) A Census of the Vascular Plants of Victoria. 8th Edn. Royal Botanic Gardens Melbourne.

Wildscape Restoration. (2010) About Wildscape Restoration. Available at www.wildscaperestoration.com/pages/projects.html (verified 02 June 2010).

Global present distribution data references

Australian National Herbarium (ANH) (2009) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at
http://www.anbg.gov.au/avh/ (verified 02 June 2010).

Calflora: Information on California Plants for Education, Research and Conservation. [web application]. (2010) Berkeley, California: The Calflora Database. [a non-profit organization]. Available at http://www.calflora.org/ (verified 02 June 2010).

Department of the Environment and Heritage (Commonwealth of Australia). (1993 – On-going) Australian Plant Name Index (APNI). Available at
http://www.cpbr.gov.au/apni/index.html (verified 02 June 2010).

Department of Sustainability and Environment (DSE). (2006) Flora Information System [CD-ROM]. Biodiversity and Natural Resources Section, Viridans Pty Ltd, Bentleigh.

Global Biodiversity Information Facility (GBIF). (2010) Global Biodiversity Information Facility. Available at http://www.gbif.org/ (verified 02 June 2010).

Integrated Taxonomic Information System. (2010) Available at http://www.itis.gov/ (verified 02 June 2010).

Missouri Botanical Gardens (MBG). (2010) w³TROPICOS, Missouri Botanical Gardens Database. Available at http://mobot.mobot.org/W3T/Search/vast.html (verified 02 June 2010).

United States Department of Agriculture. (2010) Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. Taxonomy Query. Available at http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl (verified 02 June 2010).

Feedback

Do you have additional information about this plant that will improve the quality of the assessment?
If so, we would value your contribution. Click on the link to go to the feedback form.

Page top