Research directed by C. Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service

Information on Risk Assessments
Original risk assessment

Syngonium podophyllum (American evergreen, arrowhead plant, goosefoot plant)

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

n

1.02

Has the species become naturalized where grown?

y=-1, n=-1

y

1.03

Does the species have weedy races?

y=-1, n=-1

n

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

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

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

3.02

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

n=0

n

3.03

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

n=0

y

3.04

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

n=0

y

3.05

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

n=0

n

4.01

Produces spines, thorns or burrs

y=1, n=0

n

4.02

Allelopathic

y=1, n=0

n

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

4.05

Toxic to animals

y=1, n=0

y

4.06

Host for recognized pests and pathogens

y=1, n=0

n

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

y

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

4.09

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

y=1, n=0

y

4.1

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

y=1, n=0

n

4.11

Climbing or smothering growth habit

y=1, n=0

y

4.12

Forms dense thickets

y=1, n=0

n

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

n

5.03

Nitrogen fixing woody plant

y=1, n=0

n

5.04

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

y=1, n=0

n

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

6.02

Produces viable seed.

y=1, n=-1

6.03

Hybridizes naturally

y=1, n=-1

y

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

y

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

6.07

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

See left

7.01

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

y=1, n=-1

y

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

n

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

7.08

Propagules survive passage through the gut

y=1, n=-1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

n

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

n

8.04

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

y=1, n=-1

y

8.05

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

y=-1, n=1

Total score:

15

Notes

Source

1.01

No evidence.

1.02

(1)Spreading in the national parks in Samoa and sometimes naturalizing in Tonga. Invasive in Niue (2)Escaped to hammocks in Florida

(1)http://www.hear.org/pier3/sypod.htm (2)Long and Lakela, A flora of Tropical Floria. Miami University Press, Miami

1.03

No evidence.

2.01

Native range: Central America from Mexico to Panama. ...Spreading in the national parks in Samoa and sometimes naturalizing in Tonga. Invasive in Niue

http://www.hear.org/pier3/sypod.htm

2.02

2.03

(1)Zones 10 to 11A. (2)Needs moist soil, humidity (3)It ranges from sea level to usually less than 1000 m and is more abundant below 750 m, especially between 100 and 500 m.In Central America it is most frequent in regions of tropical moist forest but also occurs in premontane wet forest. It is replaced by S. macrophyllum in tropical wet forest life zones.

(1)Plant Masterv 5.5 (2)http://www.desert-tropicals.com/Plants//Araceae/Syngonium_podophyllum.html (3)http://www.aroid.org/genera/syngonium/species/podophyllum.htm

2.04

Native range: Central America from Mexico to Panama.

http://www.hear.org/pier3/sypod.htm

2.05

Introduced to several islands in the Pacific.

http://www.hear.org/pier3/sypod.htm

3.01

(1)Spreading in the national parks in Samoa and sometimes naturalizing in Tonga. Invasive in Niue (2)Escaped to hammocks in Florida

(1)http://www.hear.org/pier3/sypod.htm (2)Long and Lakela, A flora of Tropical Floria. Miami University Press, Miami

3.02

No evidence.

3.03

Common weed in El salvdor.

Holms et al. An electronic atlas to world weeds and invasive species. CD-ROM database. Version 1.

3.04

(1)Florida: Category I - Invasive exotic (2)Invasive in Niue.

(1)http://www.fleppc.org/01list.htm(2)http://www.hear.org/pier3/sypod.htm

3.05

No evidence.

4.01

No evidence.

4.02

No evidence.

4.03

No evidence.

4.04

No information

4.05

(1)toxic to pets (2)poison to pets

(1)http://www.dublinvet.com/petinfo/toxicplants.htm (2)http://www.petroglyphsnm.org/petperil.pdf

4.06

(1)This website lists 19 fungi to be associated with S. podophyllum. (2)leaf spots, fungal diseases, root rot, spider mites, mealybugs (often common), aphids, scales

(1)http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm (2)http://pss.uvm.edu/pss123/folneph.html

4.07

(1) '...sap may irritate skin and all parts may cause stomach upset if ingested.' (2)All parts are poisonous. Irritates lips, tongue and throat. Toxic principle - calcium oxalate crystals. Causes severe pain in the mouth if eaten. (3)should be removed from any environment where children play

(1)http://pss.uvm.edu/pss123/folneph.html (2)http://www.ces.ncsu.edu/depts/hort/consumer/poison/Syngopo.htm (3)http://www.safekid.org/plants.htm

4.08

Unlikely - an evergreen vine of wet forests.

http://www.aroid.org/genera/syngonium/species/podophyllum.htm

4.09

(1)Grows under shady conditions (2)Light shade to shade

(1)http://www.hear.org/pier3/sypod.htm (2)http://www.desert-tropicals.com/Plants//Araceae/Syngonium_podophyllum.html

4.1

(1)Grows in sandy and loam soils. (2)pH range 5.5 to 6.5 (3)Moist, well-drained soils

(1)Plant Master 5.5 CD-ROM database. (2)http://www.neoflora.com/cgi-bin/plant_profile.cgi?plant_sid=14039 (3)Whistler, W.A. 2000 Tropical ornamentals. Timber Press, Portland.

4.11

type: vine

horticopia plant master, cd-rom database

4.12

No evidence

5.01

type: vine

horticopia plant master, cd-rom database

5.02

type: vine

horticopia plant master, cd-rom database

5.03

type: vine

5.04

6.01

Mostly, if not exclusively, vegetative

http://www.hear.org/pier3/sypod.htm

6.02

Always propagated vegetatively, although might rarely produce viable seeds at least in native range. Many voucher specimens are "sterile" even from native range (lacking flowers)

http://www.aroid.org/genera/syngonium/species/podophyllum.htm

6.03

In Central America S. podophyllum is most closely related to and confused with S. angustatum. The two species occur together in similar habitats throughout much of their range in Central America, and according to Birdsey (1955) they may hybridize.

http://www.aroid.org/genera/syngonium/species/podophyllum.htm

6.04

6.05

Black scarab beetles [based on congener, and Philodendron, are morphologically very similar]

http://www.aroid.org/pollination/beath/index.html

6.06

(2) Breaks readily when pulled; roots from nodes; difficult to control;

(1)http://www.hear.org/pier3/sypod.htm (2)http://edis.ifas.ufl.edu/BODY_WG209

6.07

No information

7.01

many populations are the result of discarded landscape material.

http://edis.ifas.ufl.edu/BODY_WG209

7.02

ornamental plant

7.03

no evidence

7.04

Fruit, brown-to-black berries

Whistler, W.A. 2000 Tropical ornamentals. Timber Press, Portland.

7.05

Fruit, brown-to-black berries

Whistler, W.A. 2000 Tropical ornamentals. Timber Press, Portland.

7.06

Fruit, brown-to-black berries

Whistler, W.A. 2000 Tropical ornamentals. Timber Press, Portland.

7.07

unlikely, no means of attachment, small seeds

http://www.hear.org/pier3/sypod.htm

7.08

Fruit, brown-to-black berries

Whistler, W.A. 2000 Tropical ornamentals. Timber Press, Portland.

8.01

'...seeds many, ovoid, 7-11 mm long, 5-7 mm wide, black or brown, enveloped in a soft, grayish, sweet, pulpy mesocarp.'

http://www.hear.org/pier3/sypod.htm

8.02

8.03

Hand pull vegetation, remove from site, spray resprouts with 3% Roundup or apply 10% Garlon 4 to stems. Foliar appliction of 3% Garlon 4 in water with surfactant has also acheived reasonable
success. Multiple treatments are required.

http://edis.ifas.ufl.edu/BODY_WG209

8.04

Breaks readily when pulled; roots from nodes;

http://edis.ifas.ufl.edu/BODY_WG209

8.05