Pacific Island Ecosystems at Risk (PIER)


Tradescantia spathacea


RISK ASSESSMENT RESULTS: High risk, score: 11


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

Tradescantia spathacea Sw. Family - Commelinaceae. Common Names(s) - boat-lily, moses-in-the-cradle, oysterplant. Synonym(s) - Rhoeo discolor (L'Hér.) Hance, Rhoeo spathacea (Sw.) Stearn, Tradescantia discolor (L'Hér.).

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

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

y

2

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

4.05

Toxic to animals

y=1, n=0

y

1

4.06

Host for recognized pests and pathogens

y=1, n=0

n

0

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

n

0

4.09

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

y=1, n=0

y

1

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

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

y

1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

y

1

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

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

y

1

7.05

Propagules water dispersed

y=1, n=-1

n

-1

7.06

Propagules bird dispersed

y=1, n=-1

n

-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

n

-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

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

8.05

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

y=-1, n=1

Total score:

11

Supporting data:

Notes

Source

1.01

No evidence.

 

1.02

1.03

2.01

(1) Native to: Belize; Guatemala; Mexico - Chiapas, Tabasco, Yucatan; Antigua and Barbuda; Barbados; Grenada; Guadeloupe; Jamaica; Martinique; St. Lucia; St. Vincent and Grenadines. (2) Native to southern Mexico, Guatemala, and Belize and widely naturalized in the West Indies.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?317804 [Cited 2009 April 22]. (2) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

2.02

(1) Native to: Belize; Guatemala; Mexico - Chiapas, Tabasco, Yucatan; Antigua and Barbuda; Barbados; Grenada; Guadeloupe; Jamaica; Martinique; St. Lucia; St. Vincent and Grenadines. (2) Native to southern Mexico, Guatemala, and Belize and widely naturalized in the West Indies.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?317804 [Cited 2009 April 22]. (2) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

2.03

(1) USDA hardiness zones: 9B through 11. (2) USDA zones 9-11.

(1) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22]. (2) http://www.floridata.com/ref/T/trad_spa.cfm [Cited 2009 April 22].

2.04

(1) Naturalized in Florida in cultivated grounds, pinelands, and coastal tropical hammocks. (2) Native to: Belize; Guatemala; Mexico - Chiapas, Tabasco, Yucatan; Antigua and Barbuda; Barbados; Grenada; Guadeloupe; Jamaica; Martinique; St. Lucia; St. Vincent and Grenadines. (3) Native to southern Mexico, Guatemala, and Belize and widely naturalized in the West Indies.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22]. (2) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?317804 [Cited 2009 April 22]. (3) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

2.05

(1) Widely cultivated, naturalized in temperate Asia, s.e. United States (Florida), Seychelles, & Micronesia.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?317804 [Cited 2009 April 22].

3.01

(1) Naturalized in Florida in cultivated grounds, pinelands, and coastal tropical hammocks. (2) Naturalized in Kruger National Park South Africa.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22]. (2) Foxcroft, L., Richardson D., Wilson J.R.U., 2008. Ornamental Plants as Invasive Aliens: Problems and Solutions in Kruger National Park, South Africa. Environmental Management 41(1): 32-51.

3.02

(1) Considered to be highly invasive in Florida, forms extensive colonies. Controlled by hand pull and removal from site.

(1) Langeland K.A., Stocker R.K. Control of non-native plants in natural areas of Florida. University of Florida Extension. Institute of Food and Agricultural Sciences. SP 242. 34 p.

3.03

No evidence.

 

3.04

(1) Considered to be highly invasive in Florida, forms extensive colonies. Controlled by hand pull and removal from site. (2) Tradescantia spathacea has escaped into coastal tropical hammocks in Florida, where the dense cover prevents seedling growth of native canopy trees. (3) On Ma‘uke and Niue, large areas of Tradescantia spathacea are growing in the forest understory, on rocks, etc. with the potential to form dense low stands, excluding other species.

(1) Langeland K.A., Stocker R.K. Control of non-native plants in natural areas of Florida. University of Florida Extension. Institute of Food and Agricultural Sciences. SP 242. 34 p. (2) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22]. (3) Space J.C., Flynn T. 2002. Report to the Government of the Cook Islands on Invasive Plant Species of Environmental Concern. Honolulu, Hawaii. U.S.D.A. Forest Service. Pacific Southwest Research Station. Institute of Pacific Islands Forestry. 148 p.

3.05

(1) Tradescantia fluminensis is classified as a Category I exotic invasive by the Florida Exotic Pest Plant Council. Category I invasives alter native plant communities by displacing native species, change community structures or ecological functions, or hybridize with natives.

(1) http://www.fleppc.org/eddmaps/species/ {Cited 2009 April 22].

4.01

(1) No spines, thorns or burrs.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

4.02

Unknown

4.03

(1) Not parasitic.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

4.04

Unknown (1) Leaves eaten or nibbled by ducks, dogs, raccoons..

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

4.05

(1) Poisonous to mammals.

(1) http://books.google.com/books?id=gZlWfNTm-boC&pg=PA501&dq=Tradescantia+spathacea [Cited 2009 April 22].

4.06

(1) Host for Phytophthora sp., Pythium sp., Alternaria sp., Curvularia eragrostidis, Colletotrichum sp., Phyllosticta sp., Rhizoctonia solani. (2) Caterpillars and mites can be a problem. Fungus, root rot, and leaf spot can be a problem, especially if plants are irrigated.

(1) Standish R.J. 2001. Prospects for biological control of Tradescantia fluminensis Vell. (Commelianaceae). DOC Science Internal Series 9. Wellington, New Zealand. Department of Conservation. (2) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22].

4.07

(1) Tradescantia spathacea is toxic if large quantities are eaten. Ingestion causes severe pain in the mouth, irritation of the lips, mouth, tongue, and throat, also abdominal pain. Skin irritation is minor or lasts only for a few minutes. (2) Watery sap can cause contact dermatitis, avoid getting sap on skin. Also can cause digestive problems if consumed in large quantities. [questionable whether people will eat "large quantities"; minor skin irrigation may be caused by sap of most plant species if left on the skin]

(1) http://www.ces.ncsu.edu/depts/hort/consumer/poison/Rhoeosp.htm [Cited 2009 April 22]. (2) http://florawww.eeb.uconn.edu/198500595.html [Cited 2009 April 22].

4.08

Unlikely (1) Short-stemmed tender foliage plant. Herbaceous perennial.

(1) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22].

4.09

(1) Thrives under full sun but also forms a luxuriant carpet in the shade. (2) Grows in part shade/part sun; grows in the shade.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI. (2) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22].

4.10

(1) Soil tolerances: alkaline, clay, sand, acid and loam.

(1) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22].

4.11

(1) Erect rosette plant, bromeliad-like.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

4.12

(1) Perennial herb with short, stout stem nearly hidden by overlapping leaf bases. Forms clumps by offshoots from fleshy rootstock. Leaves spreading-erect closely overlapping in spiral pattern. Blades broadly linear, sharp-tipped, somewhat fleshy, 15-30 cm long and 2.5-8 cm wide.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

5.01

(1) Terrestrial.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

5.02

(1) Commelinaceae

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

5.03

(1) Herbaceous perennial.

(1) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22].

5.04

(1) Perennial herb. Forms clumps by offshoots from fleshy rootstock.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

6.01

No evidence.

 

6.02

(1) Seldom grown by seed, but it is possible to do so. (2) Spreads from cultivation by seeds and self-propagation of offshoots.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI. (2) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

6.03

Unknown (1) Studies of the American species of Tradescantia have shown that interspecific hybridization is comparatively frequent between the eighteen or more species closely related to Tradescantia virginiana. (2) Tradescantia canaliculata Rafin. And Tradescantia humilis Rose produce natural hybrids.

(1) Anderson, E. and L. Hubricht 1938. "Hybridization in Tradescantia. III. The Evidence for Introgressive Hybridization." American Journal of Botany 25(6): 396-402. (2) http://www.genetics.org/cgi/reprint/25/5/438.pdf [Cited 2009 April 23].

6.04

(1) Self-pollinated.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

6.05

(1) Pollinated by insects.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

6.06

(1) Propagation is by division of large clumps or replanting suckers that form around the base of mature plants. (2) Roots renewed easily when pulled up or broken. Forms clumps of offshoots from fleshy rootstock. Spreads readily from cultivation by seeds and self-propagation of offshoots.

(1) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI. (2) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

6.07

(1) Slow growth rate. (2) Fast growing.

(1) http://hort.ufl.edu/shrubs/RHOSPAA.PDF [Cited 2009 April 22]. (2) http://books.google.com/books?id=WxW4Scq6kU8C&pg=PA177&dq=Tradescantia+spathacea [Cited 2009 April 23].

7.01

(1) Dispersed as discarded garden waste. Plant cuttings are a frequent source of new weed infestations. Physical transportation of plant segments in soil is a major method of spread.

(1) http://www.invasivespecies.net/database/species/ecology.asp?si=493&fr=1&sts= [Cited 2009 April 22].

7.02

(1) Cultivated widely in the tropics and elsewhere. (2) A common ornamental in Hawai‘i and the tropics.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22]. (2) Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants Cultivated in the Hawaiian Islands and Other Tropical Places. Bishop Museum Press. Honolulu, HI.

7.03

No evidence of produce contamination.

 

7.04

(1) Wind dispersed.

(1) http://www.floridata.com/ref/T/trad_spa.cfm [Cited 2009 April 22].

7.05

(1) Wind dispersed.

(1) http://www.floridata.com/ref/T/trad_spa.cfm [Cited 2009 April 22].

7.06

(1) Wind dispersed. (2) Fruit a two-seeded capsule, in clusters within the bract.

(1) http://www.floridata.com/ref/T/trad_spa.cfm [Cited 2009 April 22]. (2) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

7.07

No external means of attachment. (1) Fruit a two-seeded capsule, in clusters within the bract.

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

7.08

Not ingested (1) Fruit a two-seeded capsule in clusters in the bract

(1) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22].

8.01

(1) Flowers all year. (2) Fruit a two-seeded capsule in clusters in the bract

(1) http://plants.ifas.ufl.edu/misc/pdfs/rhospa.pdf [Cited 2009 April 22]. (2) http://www.fleppc.org/ID_book/Rhoeo%20spathacea.pdf [Cited 2009 April 22]

8.02

(1) Seed does not store well. Sow as soon as possible. (2) Seeds to be sown as soon as possible.

(1) http://davesgarden.com/guides/pf/go/650/ [Cited 2009 April 23]. (2) http://jennysgarden.com/Perennial-Other/Trandescantia_spathacea-oyster.htm [Cited 2009 April 23].

8.03

Unknown (1) Garlon 4 was used with a cut stump treatment to remove Tradescantia spathacea from Matheson Hammock Park in Florida.

(1) http://myfwc.com/docs/WildlifeHabitats/InvasivePlants_Uplands_03-04_southeast.pdf [Cited 2009 April 22].

8.04

Unknown

8.05

Unknown


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