Silver Podalyria (Podalyria sericea)

Present distribution

Scientific name:	Podalyria sericea (Andrews) R. Br.
Common name(s):	Silver Podalyria, Silky Podalyria

Map showing the present distribution of this weed.

Habitat:

Native to Cape Province of South Africa, occurring in sandstone & granite outcrops to 500m; sandy flats & hillsides (Viljoen (SANBI) 2007) & in ‘West Coast Renosterveld’ (BCA 2005) a low shrub community occurring where annual rainfall is 300mm to 600mm (Robelo 1996). In WA, a garden escape on wasteland, road verges (Hussey et al 1997), hillsides in sandy clay, ironstone gravel, laterite, granite, limestone (Florabase WA 2007). ‘Amongst tall trees, low (sclerophyll) shrubland; in gravely soil, sand, loam, clay; occupying disturbed wooland, open road verges; growing in gravel pits, in disturbed natural vegetation (Florabase WA 2007)’. In New Zealand, coastal sites (NZ PCN 2005). In Victoria, invades dry sclerophyll forest & woodland (Carr et al 1992) & established in coastal scrubland (Walsh & Entwisle 1996).

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:
Forestry; horticulture perennial; pasture dryland

Broad vegetation types
Coastal; heathland; grassy/heathy dry forest; lowland forest; foothills forest; forby forest; granitic hillslopes; rocky outcrop shrubland; western plains woodland; semi-arid woodland; alluvial plains woodland; ironbark/box; chenopod shrubland; chenopod mallee; hummock-grass mallee; lowan mallee; broombush whipstick

Colours indicate possibility of Podalyria sericea 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 silver podalyria

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

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Upright shrub to 1.5m tall (Hussey 2007) to 2.5m tall (Florabase WA 2007). Naturalised in coastal scrubland on Mornington Penisular (Walsh & Entwisle 1996). Potential to impede individual access, e.g. to beaches, possible low nuisance value.	ML	ML
2. Reduce tourism?	No information found to suggest an affect on recreational use. Native to the Cape province of South Africa (Viljoen 2007) species may be mistaken for a native. Unlikely to be obvious to the average visitor.	L	M
3. Injurious to people?	No information found to indicate this species possesses any properties injurious to people (Hussey et al 2007, Walsh & Entwisle 1996, Viljoen 2007, Florabase WA 2007)	L	M
4. Damage to cultural sites?	A small to medium shrub (Walsh & Entwisle 1996, Hussey et al 2007). No information to indicate it would cause damage to cultural sites or infrastructure.	L	M
Abiotic
5. Impact flow?	Described growing only in terrestrial habitats (Hussey et al 2007, Walsh & Entwisle 1996, Viljoen 2007, Florabase WA 2007). No impact on water flow.	L	MH
6. Impact water quality?	Described growing only in terrestrial habitats (Hussey et al 2007, Walsh & Entwisle 1996, Viljoen 2007, Florabase WA 2007). No impact on water quality.	L	MH
7. Increase soil erosion?	Described growing in coastal sites (Walsh & Entwisle 1996, NZ PCN 2005), areas of potential high erosion, however, there was no information to indicate its presence would increase the risk of erosion.	L	M
8. Reduce biomass?	Invades sclerophyll forest & woodland (Carr et al 1992) & naturalised in coastal scrubland (Walsh & Entwisle 1996) and is an upright shrub to 1.5m tall (Hussey 2007) to 2.5m tall (Florabase WA 2007) – direct replacement of biomass	ML	M
9. Change fire regime?	Described as a component of Renosterveld in South Africa, “a fire prone shrubland” (WWF 2001) and described invading communities that experience fires with reasonable regularity such as coastal shrubland (Walsh & Entwisle 1996) and dry sclerophyll forest & woodland (Carr et al 1992) so it is unlikely to cause a change of fire regime in these habitats. “Too frequent fires” (Viljoen 2007) is documented as one of the reasons this species is threatened in south Africa so it is unlikely to have traits that increase fire risk and no suggestion of decreasing fire risk.	L	M
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Alluvial Terrace Herb-rich Woodland (V); CMA = North Central; Bioregion = Goldfields; VH CLIMATE potential. Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992)’ & naturalised in coastal scrubland (Walsh & Entwisle 1996) – likely to have a major displacement of some dominant specie within the understory layer.	MH	MH
(b) medium value EVC	EVC = Heathy Herb-rich Woodland (D/R); CMA = Wimmera; Bioregion = Wimmera; VH CLIMATE potential. Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992)’ & naturalised in coastal scrubland (Walsh & Entwisle 1996) – likely to have a major displacement of some dominant specie within the understory layer.	MH	MH
(c) low value EVC	EVC = Heathy Woodland (LC); CMA = Port Phillip and Western Port; Bioregion = Gippsland Plain; VH CLIMATE potential. Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992)’ & naturalised in coastal scrubland (Walsh & Entwisle 1996) – likely to have a major displacement of some dominant specie within the understory layer.	MH	MH
11. Impact on structure?	Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992)’ & naturalised in coastal scrubland (Walsh & Entwisle 1996) – likely to have a major effect on <60% of the floral strata	MH	MH
12. Effect on threatened flora?	Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992) and is naturalised in coastal scrubland (Walsh & Entwisle 1996). However, the effect of threatened flora is not yet determined	MH	L
Fauna
13. Effect on threatened fauna?	Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992) and is naturalised in coastal scrubland (Walsh & Entwisle 1996). However, the effect on threatened fauna is not yet determined	MH	L
14. Effect on non-threatened fauna?	Described as a “potential threat to one or more vegetation formations in Victoria.” Invades sclerophyll forest & woodland (Carr et al 1992) and is naturalised in coastal scrubland (Walsh & Entwisle 1996). It is likely to change shrub layer habitat and food sources – reduction in habitat for fauna spp., leading to reduction in numbers of individuals	MH	MH
15. Benefits fauna?	“Flowers are visited by carpenter bees and many other insects.” Grazing is described as one reason that it is threatened in South Africa (Viljoen 2007) which is an indication it could provide a food source to grazing mammals in Australia. Shrub to 1.5m tall (Hussey et al 2007) to 2.5m tall (Florabase WA 2007); could provide harbour to small mammal and bird species. Likely to provide some assistance in shelter or food to desirable species.	MH	ML
16. Injurious to fauna?	Grazing is described as one reason that it is threatened in South Africa (Viljoen 2007). There was no information found to indicate this species possesses any properties injurious to fauna.	L	M
Pest Animal
17. Food source to pests?	“Flowers are visited by carpenter bees and many other insects” (Viljoen 2007). Potential to provide a food source to honey bees.	ML	M
18. Provides harbor?	Upright shrub to 1.5m tall (Hussey et al 2007) to 2.5m tall (Florabase WA 2007). Invades coastal areas, wasteland, hillsides, road verges, disturbed natural vegetation etc (Hussey et al 1997, Florabase WA 2007, NZ PCN 2005, Walsh & Entwisle 1996). Has the capacity to provide temporary harbour to rabbits.	MH	M
Agriculture
19. Impact yield?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996) – little or negligible affect on quantity of yield	L	MH
20. Impact quality?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996) – little or negligible affect on quality of yield	L	MH
21. Affect land value?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996) – little or none	L	MH
22. Change land use?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996) – little or no change	L	MH
23. Increase harvest costs?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996) – little or none	L	MH
24. Disease host/vector?	“environmental weed, naturalised” (Randall 2002), not described as a weed of agriculture (Walsh & Entwisle 1996). Disease host/vector not mentioned in the literature – unknown	M	L

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	“it does not tolerate frost…Best grown from seed sown in autumn or spring” (Viljoen 2007). Appears to require natural seasonal disturbances such as mild seasonal temperatures to germinate.	MH	M
2. Establishment requirements?	Grows best in full sun (Viljoen 2007) and well at coastal sites (NZ PCN 2005) but also documented as an invader of dry sclerophyll forest/ woodland (Carr et al 1992) and described to occur “Amongst tall trees” (Florabase WA 2007). Appears capable of establishing under a moderate canopy.	MH	M
3. How much disturbance is required?	In Victoria described as invading dry sclerophyll forest & woodland (Carr et al 1992) & as “apparently established in coastal scrubland near Mornington” (Walsh & Entwisle 1996). Potential to establish in minor disturbed natural ecosystems.	MH	M
Growth/Competitive
4. Life form?	Small to medium leguminous, perennial shrub. Height to 1 m (NZ PCN 2005). Fabaceae (Walsh & Entwisle 1996).	MH	MH
5. Allelopathic properties?	There is no evidence to suggest Allelopathy of this species.	L	M
6. Tolerates herb pressure?	Grazing is described as one reason that it is threatened in South Africa (Viljoen 2007) – eliminated by moderate herbivory	l	m
7. Normal growth rate?	Moderate growth rate (Viljoen 2007)	M	M
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Drought tolerant. Susceptible to frost. Does not grow well in alkaline soils (Viljoen 2007). Occurs at coastal sites, “Can tolerate salt” (NZ PCN 2005). Drought and salt tolerant and occurs in the vegetation community Renosterveld (BCA 2005) a fire prone shrubland (WWF 2001) so likely to display some tolerance to fire.	MH	M
Reproduction
9. Reproductive system	Spreading by seed (Swarbrick and Skarratt, 1994). Information on whether it self or cross pollinates was not found.	ML	ML
10. Number of propagules produced?	“Pod 2.5-3cm long…seeds several” (Walsh & Entwisle 1996). Small, single flowers “are dotted all over the bush from May to August.” Flowers are followed by pods, containing several small seeds. Images show a pod containing 4 seeds (Viljoen 2007) and 250 + pods per plant appears possible based on images - 1000+ seeds.	MH	M
11. Propagule longevity?	Seeds may have prolonged dormancy (Swarbrick and Skarratt 1994). “Most Fabaceae are described as developing long-lived seeds” (Baskin & Baskin 2001). Fabaceae seeds 100-200 years and older are described germinating in a number of circumstances (BGT 2006)’. Potential for seeds to survive 20+ years.	H	M
12. Reproductive period?	Perennial shrub (NZ PCN 2005). Mature plant produces viable propagules for at least 3-10 years.	MH	M
13. Time to reproductive maturity?	Time to reproductive maturity was not found described.	M	L
Dispersal
14. Number of mechanisms?	Human dispersal and seed spread via gravity are documented (NZ PCN 2005). Described as an ornamental (NZ PCN 2005) and a garden escape (Hussey et al 1997). Deliberate human dispersal likely.	ML	M
15. How far do they disperse?	Human introduction (NZ PCN 2005) and dispersal of plants or seeds could spread propagules greater than 1km.	H	M

References

Allsop, N. and Stock, WD. (1995) Relationships between Seed Reserves, Seedling Growth and Mychorrhizal Responses in 14 Related Shrubs (Rosidae) from a Liw-Nutrient Environment. In: Functional Ecology. Vol. 9 (2).

Aluka Species Information (2006, 2007) Ithaka Harbors, Inc. http://www.aluka.org/action/showMetadata?doi=10.5555/AL.AP.VISUAL.NBGSLD0003640&pgs=. (Accessed 11 Dec., 2007).

Australian National Herbarium (ANH) (2006) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research. http://www.anbg.gov.au/cgi-bin/avh.cgi. (Accessed 11 Dec., 2007).

Baskin CC, Baskin JM (2001) Seeds: ecology, biogeography, and evolution of dormancy and germination. Academic Press.

Blaauwberg Conservation Area (BCA) (2005) Floral Treasures. Blaauwberg Conservation Area, City of Cape Town. http://web.capetown.gov.za/eDocuments/BCA_Floral_Treasures_brochure_23112006163215_465.pdf (Accessed 11 Dec., 2007).

Bond, WJ., Honig, M. and Maze, KE. (1999) Seed size and seedling emergence: an allometric relationship and some ecological implications. In: Oecologia. Vol. 120 (1).

Botanic Gardens Trust (BGT) (2006) Seed Research. Department of Environment and Climate Change NSW, Sydney. Available at http://www.rbgsyd.nsw.gov.au/science/hot_science_topics/nsw_seedbank/seed_research (Accessed 11 June 2008)

Carr GW (1992) Environmental weed invasions in Victoria: conservation and management implications. Department of Conservation and Environment

FloraBase, the Western Australian Flora (2007) Western Australian Herbarium, Department of Environment and Conservation. http://florabase.dec.wa.gov.au/browse/map/17016. (Accessed 11 Dec., 2007).

Global Biodiversity Information Facility (GBIF) (2007) Global Biodiversity Information Facility. http://newportal.gbif.org/species/13626191/. (Accessed 11 Dec., 2007)

Hussey BMJ (2007) Western weeds: a guide to weeds of Western Australia. Weed Society of Western Australia.

International Legume Database & Information Service (2005) ITIS, Species 2000, Catalogue of Life: 2006 Annual Checklist. http://www.ildis.org/LegumeWeb/6.00/taxa/2958.shtml. (Accessed 11 Dec., 2007).

International Legume Database & Information Service (2005) ITIS, Species 2000, Catalogue of Life: 2006 Annual Checklist. http://www.ildis.org/LegumeWeb/6.00/taxa/2940.shtml. (Accessed 11 Dec., 2007).

Moore, L.B.; Edgar, E. (1970) Flora of New Zealand. Vol. 2. Indigenous Tracheophyta - Monocotyledons except Graminae. First electronic edition,
Landcare Research, June 2004. Transcr. A.D. Wilton and I.M.L. Andres.
(http://floraseries.landcareresearch.co.nz/pages/ChapterType.aspx?id=_9118c215-b7c0-45a0-af7d-4719028d2922&fileName=Flora%204.xml (Accessed 11 Dec., 2007).

New Zealand Plant Conservation Network (NZ PCN) (2005) Weed information. New Zealand Plant Conservation Network. http://www.nzpcn.org.nz/exotic_plant_life_and_weeds/detail.asp?WeedID=717. (Accessed 11 Dec., 2007).

Plant Protection Society of WA Dicotyledons Information (19**) Plant Protection Society of WA. http://members.iinet.net.au/~weeds/western_weeds/fabaceae_3.htm. (Accessed 11 Dec., 2007).

Randall R (2002) A global compendium of weeds. RG and FJ Richardson, Melbourne.

Viljoen C (2007), Kirstenbosch Garden, South African National Biodiversity Institute, South Africa. http://www.plantzafrica.com/plantnop/podalyrseri.htm. (Accessed 12 Dec., 2007).

United States Department of Argiculture (USDA) (2006) Germplasm Resources Information Network (GRIN), Agricultural Research Service. http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?29029. (Accessed 11 Dec., 2007).

Zip Code Zoo (2004-1007) The BayScience Foundation, Inc. http://zipcodezoo.com/Plants/P/Podalyria_sericea.asp. (Accessed 11 Dec., 2007).

Rebelo A (1996), 62. West Coast Renosterveld/ Renosterveld. In: Low AB & Robelo AG (eds) Vegetation of South Africa, Lesotho and Swaziland. Department of Environmental Affairs and Tourism, Pretoria. Available at http://www.environment.gov.za/soer/nsoer/Data/vegrsa/Renoster.htm (verified 11 June 2008)

Swarbrick JT, Skarratt DB (1994) The bushweed 2 database of environmental weeds in Australia. The University of Queensland Gatton College.

Walsh N and Entwisle T. (Eds.) (1996) Flora of Victoria: Volume 3. Dicotyledon;s Winteraceae to Myrtaceae, Inkata Press, Melbourne. http://www.rbgsyd.nsw.gov.au/science/hot_science_topics/nsw_seedbank/seed_research#lon

World Wildlife Fund (WWF), McGinley M (2007). Montane fynbos and renosterveld. In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). (First published in the Encyclopedia of Earth April 3, 2007; Last revised April 19, 2007). Available at http://www.eoearth.org/article/Montane_fynbos_and_renosterveld (Accessed 11 June 2008)

World Wildlife Fund (WWF) (2001) Wild world ecoregion profile; Lowland fynbos and renosterveld (AT1202). Available at www.ngeo.com/wildworld/profiles/terrestrial/at/at1202.html (Accessed 11 June 2008)

Global present distribution data references

African Flowering Plants Database. 2007. South African National Biodiversity Institute, Available at, http://www.ville-ge.ch/cjb/bd/africa/details.php?langue=an&id=68784 (verified 12 June 2008).

Australian National Herbarium (ANH) (2008) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at http://www.anbg.gov.au/avh/ (verified 04 June 2008).

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) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 04 June 2008)

Manaaki Whenua Landcare Research 2006. Nga Tipu o Aotearoa- New Zealand Plants, Available at http://nzflora.landcareresearch.co.nz/ (verified 11/06/08)

PlantzAfrica. Plants of Southern Africa. South African National Biodiversity Institute. Available at http://www.plantzafrica.com/frames/plantsfram.htm (verified 12 June 2008).

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