Water poppy (Hydrocleys nymphoides)

Present distribution

Scientific name:	Hydrocleys nymphoides (Humb. & Bonpl. Ex Willd.) Buch.
Common name(s):	water poppy

Map showing the present distribution of this weed.

Habitat:

In Australia, it is naturalised in slow moving, nutrient rich waters. Grows by stolons and plantlets which readily colonise wet mud (CSIRO 2008). Tolerates shade but prefers sun (Speichert & Speichert 2004). Leaves may burn when temperatures drop into the 20°F (SM growers 2008). Water poppy grows rapidly in warm, well lit water bodies to depths of 2 m. (Environment Waikato 2008). Frost tender (Wild Eel 2008). Exclusive to lentic environments (Pott & Pott 2003). Subtropical, but grows well in both warm and cool temperate climates, nutrient rich conditions, freshwater weed (RNZIH 2008). Occurs in warm, well lit water bodies (BioSec NZ), streams, ponds, farm dams and lake margins (Coffey and Clayton 1988). Grows best in 20-45 cm water, can tolerate depths of 2 m. (EW.govt.nz 2008; Australian Water Gardens).

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:
Water

Ecological Vegetation Divisions
Freshwater wetland (permanent); treed swampy wetland; freshwater wetland (ephemeral)

Colours indicate possibility of Hydrocleys nymphoides infesting these areas.

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

ap showing the potential distribution of hydrocleys nymphoides

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

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Height < 1 foot, width spreading (SM growers 2008). It can completely choke streams; causing flooding and excluding native species (EWRC 2008) Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). -high nuisance value. People and vehicles access with difficulty.	MH	MH
2. Reduce tourism?	It can completely choke streams, causing flooding and excluding native species ….. forms a deep mat (EWRC 2008) - Major impact on recreation. Weeds obvious to most visitors, with visitor response complaints and a major reduction in visitors.	H	MH
3. Injurious to people?	Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). May therefore cause drowning. - Large spines or burrs extremely toxic, and cause serious allergies to humans throughout the year.	H	MH
4. Damage to cultural sites?	It can completely choke streams, causing flooding and excluding native species (EWRC 2008) - Moderate visual effect	ML	MH
Abiotic
5. Impact flow?	It can completely choke streams, causing flooding and exclude native species (Environment Waikato 2008) Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). “Stoloniferous herb sometimes taking root” (Spencer 2005). - Serious impacts both to surface and subsurface water flow (eg. Attached emergent aquatics).	H	MH
6. Impact water quality?	Recommended as a plant that helps water stay clean, but requires control – cutting back and pulling out dead leaves. (DAF Western Australia 2008). If chokes out stream, lake, or pond - covers surface will greatly reduce light availability below and possibly dissolved oxygen. - High effects in either dissolved oxygen and light; causing eutrophication.	H	MH
7. Increase soil erosion?	Stoloniferous herb sometimes taking root” (Spencer 2005). “grows by stolons and plantlets which readily colonise wet mud” (CSIRO 2002). “Creeping or floating stoloniferous plant with floating or emergent leaves” Can cause flooding – in areas where it’s not present but flooding will have moderate probability of large scale soil movement. - Moderate probability of large scale soil movement.	ML	MH
8. Reduce biomass?	In a study by Hastwell and co-workers (2008) H. nymphoides accumulated more biomass than its native relatives. It can completely choke streams, causing flooding and excluding native species (EWRC 2008) - Biomass may increase.	L	MH
9. Change fire regime?	Aquatic plant – not likely to change fire regime. – Small or negligible effect on fire risk.	L	MH
Community Habitat
10. Impact on composition (a) high value EVC	It is an aggressive coloniser of ponds, streams, farm dams and lake margins where it can spread into water depths of 2 metres (Coffee & Clayton 1988). When space is occupied by grasses etc. typical of marshland. - Major displacement of some dominant species within a strata/layer (or some dominant species within different layers)	MH	MH
(b) medium value EVC	Aquatic species. All Victorian water bodies considered to comprise high value EVCs only (Weiss pers. comms.). -Very little displacement of any indigenous species sparse/scattered infestations	L	MH
(c) low value EVC	Aquatic species. All Victorian water bodies considered to comprise high value EVCs only (Weiss pers. com). -Very little displacement of any indigenous species sparse/scattered infestations	L	MH
11. Impact on structure?	“It is an aggressive coloniser of ponds, streams, farm dams and lake margins where it can spread into water depths of 2 meters” (Coffee & Clayton 1988). It displayed weedy characters and therefore was eradicated by herbicide treatment ….is a class B noxious plant in the Rotorua district (Coffey and Clayton 1988). Form a deep mat (EBOP 2008). - Major effects on all layers. Forms monoculture; no other strata layers present.	H	MH
12. Effect on threatened flora?	“It can completely choke streams, shallow ponds and lake margins, causing flooding and excluding native species” (BioSec NZ 2008).” – can out compete/ reduce populations of native species. - Any population of bioregional Priority 1A spp is reduced, or any population of a VROT is replaced.	MH	MH
Fauna
13. Effect on threatened fauna?	“Water poppy grows rapidly in warm well lit water bodies to depths of 2 m. It can completely choke streams, shallow ponds and lake margins, causing flooding and excluding native species (BioSec NZ 2008). Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). alters the habitat for other organisms. No reports of direct effect on threatened species. – Minor effects on threatened spp.; minor hazard or reduction in habitat/food/shelter.	ML	M
14. Effect on non-threatened fauna?	“Water poppy grows rapidly in warm well lit water bodies to depths of 2 m. It can completely choke streams, shallow ponds and lake margins, causing flooding and excluding native species (BioSec NZ 2008). Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). Therefore monoculture – alters the habitat for other organisms. – Reduction in habitat for fauna spp., leading to reduction in numbers of individuals, but not to local extinction.	MH	MH
15. Benefits fauna?	Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). May provide shelter/ shade for native fish/ aquatic animals. - Provides some assistance in either food or shelter to desirable species.	MH	MH
16. Injurious to fauna?	Leaves are thick and shiny and float on the surface, with each shoot connected by a network of elastic creeping stems that form a deep mat (EBOP 2008). – may cause drowning of some animals, but not reported to be poisonous does not large spines or burrs. – no effect.	L	M
Pest Animal
17. Food source to pests?	No evidence of Hydrocleys nymphoides being a source of food. – provides minimal food for pest animals.	L	MH
18. Provides harbour?	“Hydrocleys nymphoides” is cultivated, either in aquaria or in pools and ponds. The species apparently persists following cultivation or dumping of aquaria (eFloras 2008). Not reported to harbour pest species but used in aquaria so may provide shade/ shelter and harbour some pest animals. - doesn’t provide harbour for serious pest species, but may provide harbour for minor pest species.	ML	MH
Agriculture
19. Impact yield?	Aquatic herb – unlikely to affect yield except maybe restrict access to water for irrigation or cause water loss through flooding and subsequent drainage/ evaporation increase. – Minor impact on quantity of produce (eg < 5% reduction).	ML	MH
20. Impact quality?	Aquatic herb – unlikely to affect quality except maybe restrict access to water for irrigation or cause water loss through flooding and subsequent drainage/ evaporation increase. Therefore less water available to livestock – Minor impact on quality of produce (eg < 5% reduction).	ML	MH
21. Affect land value?	Naturalised on a few farm dams and slow moving rivers in Victoria (Spencer 2005). Can be treated with herbicide or mechanical removal…. Therefore unlikely to affect land value. (RNIZH 2008; Sainty & Jacobs 2003). – Decreases in land value<10%.	ML	MH
22. Change land use?	Aquatic, - unlikely to affect land use. – Little to none.	L	MH
23. Increase harvest costs?	May restrict the ability of cattle or other live stock to gain access to water. – Minor increase in cost of harvesting – eg slightly more time or labour is required.	ML	MH
24. Disease host/vector?	No evidence of Hydrocleys nymphoides being a disease host/ vector.	M	ML

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Produces new plantlets at the end of the growth season. These break away from the main plant rise to the surface and carried by water movement to a new location before taking root in the mud (NZPCN 2008). Nutrient rich conditions (RNZIH 2008) No viable seed is produced and any new sites will be the result of deliberate planting (ENVBOP 2008). “Grows by stolons and plantlets which readily colonise wet mud (CSIRO 2008). “ rootlets should be potted and stood in water at least 15 cm deep and maintained at temperature not less than 20C” (Australian Water Gardener 2008). Requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination.	MH	MH
2. Establishment requirements?	Tolerates shade but prefers sun (Speichert & Speichert 2004). Readily colonise wet mud (CSIRO 2008). Easily grown in ponds to 1 m deep” (CSIRO 2002). Leaves may burn when temperatures drop into the 20’s°F (SM growers 2008). plantlets break away and are carried by water movement before taking root in the mud (NZPCN 2008). Exclusive to lentic environments (Applied to a freshwater habitat characterised by calm or standing water) (Pott & Pott 2003). Can establish under moderate canopy/litter cover.	MH	MH
3. How much disturbance is required?	It can completely choke streams, causing flooding and excluding native species (Environment Waikato 2008). Establishes in relatively intact or only minor disturbed natural ecosystems (e.g. Wetlands riparian, riverine, grasslands and open woodlands); in vigorously growing crops or in well-established pastures).	MH	MH
Growth/Competitive
4. Life form?	Water poppy is a water lily –like perennial plant (Environment Waikato 2008). Aquatic herb (CSIRO 2002). Aquatic (submerged, emergent, floating for ALL of life, inc. germination), and semi aquatic (some plant parts always in water).	H	MH
5. Allelopathic properties?	No Allelopathic properties mentioned in the literature. (pers.obs 2008).	M	L
6. Tolerates herb pressure?	Habit that spreads over 1-6 feet can be restrained if the gardener is willing to prune it back” (Speichert & Speichert 2004). Not enough information.	MH	M
7. Normal growth rate?	Water poppy grows rapidly in warm, well lit water bodies to depths of 2 m. (Environment Waikato 2008) In a study by Hastwell and co-workers (2008) H. nymphoides accumulated more biomass than its native relatives. Rapid growth rate that will exceed most other species of the same life form.	H	MH
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Frost tender (Wild Eel 2008). Tolerates shade but prefers sun (Speichert & Speichert 2004). Temperature range between 10 – 22C (ENVBOP 2008). Exclusive to lentic environments (Applied to a freshwater habitat characterised by calm or standing water) (Pott & Pott 2003). Maybe tolerant of one stress, susceptible to at least one.	L	MH
Reproduction
9. Reproductive system	Reproduces vegetatively (NZPCN 2008) and produces seed (CSIRO 2002). Although (ENVBOP 2008) report that no viable seed is produced in New Zealand. - Both vegetative and sexual reproduction (veg reproduction may be via cultivation, but not propagation).	H	MH
10. Number of propagules produced?	The fruit consists of a group of hard capsules each being 15 mm long with a beak. Capsules split longitudinally to release several small horse shoe-shaped seeds (CSIRO 2002). “No viable seed is produced and any new sites will be the result of deliberate planting” (ENVBOP 2008). Only vegetative spread has been reported in New Zealand but seed set is likely (Coffey & Clayton (1988). - 50-1000	ML	M
11. Propagule longevity?	Water poppy produces no seeds but spreads by extension of its creeping stems and from broken stem fragments carried by water, machinery, boats or people (RNZIH 2008). Greater than 25% of seeds survive 5 years or vegetatively reproduces.	L	M
12. Reproductive period?	Perennial…produces propagules after growing season. (NZPCN 2008). Mature plant produces viable propagules for 3-10 years.	MH	MH
13. Time to reproductive maturity?	No information on age until first production of propagules but plants produce plantlets which break away and are carried by water movement before taking root in the mud (NZPCN 2008). Aggressive coloniser (Coffee & Clayton 1988). Grows rapidly can choke out streams (Environment Waikato 2008) Propagules probably produced at least after following growing season. Produces propagules between 1-2 years after germination, or vegetative propagules become separate individuals between 1-2 years.	MH	MH
Dispersal
14. Number of mechanisms?	Introduced as an ornamental (CSIRO 2002). “Water poppy produces no seeds but spreads by extension of its creeping stems and from broken stem fragments carried by water, machinery, boats or people”. (RNZIH 2008). Propagules spread by wind, water, attachment (humans, animals, or vehicles), or accidental human dispersal (ploughing).	MH	MH
15. How far do they disperse?	Broken stem fragments carried by water, machinery, boats or people (RNZIH 2008). “Poor dispersal capacity has limited spread” (Champion et al. 2004). Broken stem fragments carried by water, machinery, boats or people”. (RNZIH 2008). Is an aquatic ornamental (CSIRO 2002). Worst case scenario is that spread is by machinery, boats and people - but natural dispersal is limited – “poor dispersal capacity has limited spread” (Champion et al. 2004). Very likely that at least one propagule will disperse greater than 1 kilometre.	H	M

References

NC State University (North Carolina State University) (2008) Hydrocleys nymphoides. http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/watergarden/
floatingplants/Hydrocleys_nymphoides.html (16 Jan 2009).

BioSecurity New Zealand (BioSec NZ) (2008). Water poppy – Hydrocleys nymphoides. http://www.biosecurity.govt.nz/pests/water-poppy (verified 16 January 2009).

Champion, P., Rowe, D., Smith, B., Richardson, J. and Reeves, P. (2004). Identification guide: freshwater pests of New Zealand. N/W Information series No. 55.

Coffey, B. T. & Clayton, J. S. (1988). New Zealand Water plants. A guide to plants found in New Zealand freshwaters. Ruakura Agricultural Centre, Hamilton, New Zealand.

CSIRO (2002). CSIRO - Wetland plants of Queensland - Limnocharitaceae. Hydrocleys nymphoides. p46. http://www.publish.csiro.au/ (verified 16 January 2009)

DAF Western Australia (Department of Agriculture and Fisheries) Garden note (2005). Guidelines for garden ponds. No. 44 http://www.agric.wa.gov.au/content/hort/ponds.pdf (16 Jan 09).

eFloras (2008) Flora of North America – Hydrocleys nymphoides. http://www.efloras.org/florataxon.aspx?flora_id=101&taxon_id=222000085 (16 Jan 2009).

(EWRC) Environment Waikato Regional Council (2008) 5 Plant Pests. Water poppy (Hydrocleys nymphoides.)- Regional-Pest-Management-Strategy.
http://www.ew.govt.nz/Policy-and-plans/Regional-Pest-Management-Strategy/Regional-Pest-Management-Strategy-2002-2007/5-Plant-Pests/52-Eradication-Service-Delivery-Plant-Pests-/5214-Water-Poppy-Hydrocleys-nymphoides/ (verified 16 January 2009)

Hastwell, G. T., Daniel, A. J. and Vivian-Smith G. (2008) Predicting invasiveness in exotic species. A Journal of Conservation Biogeography. Vol 14, Issue 2 pg 243-351. (March).

NZPCN (2008). Unwanted organism: Hydrocleys nymphoides. New Zealand Plant conservation Network.
www.nzpcn.org.nz/exotic_plant_life_and_weeds/detail.asp?WeedID=1713 (verified 01 September 2008)

Pott, A. and Pott, V. J. (2004) Features and Conservation of the Brazilian Pantanal Wetland. Wetlands Ecology and Management. 12: 547-552, Netherlands.

RNZIH (Royal New Zealand Institute of Horticulture) (2008). Water poppy (Hydrocleys nymphoides) – Floating aquatic plant. www.rnzih.org.nz/pages/nppa_091.pdf (verified 01 September 2008)

Sainty, G. & Surrey, J. (2003) Water plants in Australia. 4th ed. Sainty and Associates Pty. Ltd

SM growers (2008). San Marcos Growers. Hydrocleys Nymphoides- (Aquatic) – Water poppy. http://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=1898 (verified 16 January 2008).

Spencer, R. (2005). Horticultural Flora of South Eastern Australia. Vol 5. UNSW press.

Speichert, G. & Speichert, S. (2004). Encyclopaedia of Water Garden Plants p 320 Timber Press, Portland, Oregon, USA.

Wild Eel (2008). Hydrocleys nymphoides. http://wildeel.com/waterplant.html (Under selected aquatic plants) (9/2008).

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 15 January 2009)

Global Biodiversity Information Facility (GBIF) (2009) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 15 January 2009)

Integrated Taxonomic Information System. (2009) Available at http://www.itis.gov/ (verified 15 January 2009)

Missouri Botanical Gardens (MBG). w³TROPICOS, Missouri Botanical Gardens Database (2007). Available at http://mobot.mobot.org/W3T/Search/vast.html (verified 15 January 2009)

United States Department of Agriculture. Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. Taxonomy Query. (2008) Available at http://www.ars-grin.gov/cgi-bin/npgs/html/taxgenform.pl (verified 15 January 2009)

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