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

Citharexylum spinosum; C. quadrangulare, C.fruticosum; fiddlewood

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

n

3.04

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

n=0

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

n

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

n

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

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

y

4.11

Climbing or smothering growth habit

y=1, n=0

n

4.12

Forms dense thickets

y=1, n=0

y

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

y

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

n

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

n

6.07

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

See left

3

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

y

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

y

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

y

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

n

8.03

Well controlled by herbicides

y=-1, n=1

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:

7

Source

Notes

1.01

no evidence

1.02

(1) Challinor, D.; Wingate, D. B. (1971) The struggle for survival of the Bermuda cedar. Biological Conservation, 1971, Vol.3, No.3, pp.220-222, 6 ref.
(2) Forest Starr, Kim Martz and Lloyd Loope. 1999. Fiddlewood(Citharexylum spinosum) An Alien Plant Report. United States Geological Survey Biological Resources Division, In cooperation with: American Water Works Association Research Foundation
Maui County Board of Water Supply (http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf), Gerrish, G., and Mueller-Dombois, D. 1980. Behavior of native and non-native plants in two tropical rain forests on O'ahu, Hawaiian islands. Phytocoenologia, 8, 237-95.

(1) AB: "naturalized Pimenta officinalis, Citharexylum spinosum, Eugenia uniflora and Schinus terebinthifolius have proved very successful as replacements"
(2) "Fiddlewood can be found on the islands of O'ahu and Maui, where it is
naturalized on both islands."

1.03

no evidence

2.01

(1)USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?10664 (13 April 2002) (2)http://bermuda-online.org/flowers.htm

1)Northern America: United States - Florida [s.]
Southern America: Anguilla; Antigua and Barbuda; Bahamas; Barbados; Cuba; Dominica; Grenada; Guadeloupe; Guyana; Hispaniola; Jamaica; Martinique; Montserrat; Netherlands Antilles; Puerto Rico; St. Kitts and Nevis - St. Kitts; St. Lucia; St. Vincent and Grenadines; Suriname; Trinidad and Tobago; Venezuela (2)Originally from Tropical America

2.02

2.03

(1)Forest Starr, Kim Martz and Lloyd Loope. 1999. Fiddlewood(Citharexylum spinosum) An Alien Plant Report. United States Geological Survey Biological Resources Division, In cooperation with: American Water Works Association Research Foundation
Maui County Board of Water Supply (http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf) (2) Little and Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. USDA Forest Service. (3)Smith, Clifford W. 1985. Impact of alien plants on Hawai‘i's native biota. In: Charles P. Stone and J. Michael Scott, eds..Hawai‘i’s Terrestrial Ecosystems: Preservation and Management. Cooperative National Park Resources Studies Unit,University of Hawaii, Manoa. p. 188. (4) Long and Lakela. A Flora of Tropical Florida. University of Miami Press, Coral Gables (5)http://hort.ifas.ufl.edu/shrubs/CITFRUA.PDF (6)Adams, G.D. 1972. Flowering plants of Jamaica, University of the West Indies.

(1)In this report, there seems to be a highly questionable description of this species' distribution. "Climate where invading: Fiddlewood can be found growing in a wide range of climatic conditions, from very dry to very wet habitats and from near sea level up to 3500 feet in elevation.". In all other descriptions of this species, it is restricted to low elevation, dry sites (as reported in Hawaii by Gerrish and Mueller Dombois 1980). I believe the authors of report (1) may have confused specimens of C. caudatum at higher elevation, wet sites. C. caudatum is known to prefer such habitats. (2) Coastal, limestone, lower montain forests. (3) It grows in dry habitats generally below 500 m (4) Occurs on Hammocks, pinland, S. Florida (5)USDA hardiness zones: 10B through 11 (6) "Common in thickets and woodland on limestone, especially near the sea and on the cays"

2.04

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

Presence: Pacific islands: Fiji, French Polynesia (cultivated), Hawai‘i.

2.05

(1) USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>
(2) Ben-Dov, Y. (1987) New or little-known scale insects (Coccoidea) in Israel. Hassadeh, 1987, Vol.67, No.4, pp.801-802, 11 ref.

(1) Presence: Pacific islands: Fiji, French Polynesia (cultivated), Hawai‘i.
(2) Israel

3.01

(1) Challinor, D.; Wingate, D. B. (1971) The struggle for survival of the Bermuda cedar. Biological Conservation, 1971, Vol.3, No.3, pp.220-222, 6 ref. (2)Forest Starr, Kim Martz and Lloyd Loope. 1999. Fiddlewood(Citharexylum spinosum) An Alien Plant Report. United States Geological Survey Biological Resources Division, In cooperation with: American Water Works Association Research Foundation
Maui County Board of Water Supply (http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf), Gerrish, G., and Mueller-Dombois, D. 1980. Behavior of native and non-native plants intwo tropical rain forests on O'ahu, Hawaiian islands. Phytocoenologia, 8, 237-95.

(1) "naturalized Pimenta officinalis, Citharexylum spinosum, Eugenia uniflora and Schinus terebinthifolius have proved very successful as replacements" (2) Naturalized on O‘ahu at Tantalus and Pupukea, also on Maui in the area of Ha'iku, especially 'Ohia gulch, and in Kihei.

3.02

no evidence

3.03

Bacon, P., P.J. Terry, N. Waltham, & P.Castro S. (1997) An Electronic Atlas of World Weed and Invasive Plants. Version 1.0, 1997. A database based on the original work "A Geographical Atlas of World Weeds" by Holm et al 1979.

listed as a common weed in USA (not a significant agricultural weed)

3.04

Forest Starr, Kim Martz and Lloyd Loope. 1999. Fiddlewood(Citharexylum spinosum) An Alien Plant Report. United States Geological Survey Biological Resources Division, In cooperation with: American Water Works Association Research Foundation Maui County Board of Water Supply (http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf)

Report indicates that this species is naturalized in limited areas in Hawai‘i and it could become a problem. Not yet being controled. [Is not considered a problem in Jamaica where it is naturalized]

3.05

Bacon, P., P.J. Terry, N. Waltham, & P.Castro S. (1997) An Electronic Atlas of World Weed and Invasive Plants. Version 1.0, 1997. A database based on the original work "A Geographical Atlas of World Weeds" by Holm et al 1979.

no other species are listed as weeds

4.01

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"This evergreen, medium-sized tree does not have the spines that its scientific name suggests."

4.02

no evidence

4.03

no evidence

4.04

4.05

Little and Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. USDA Forest Service.

berries said to be sweet and edible

4.06

Jones, V. P.; Anderson-Wong, P.; Follett, P. A.; Yang PingJun; Westcot, D. M.; Hu, J. S.; Ullman, D. E. (2000) Feeding damage of the introduced leafhopper Sophonia rufofascia (Homoptera: Cicadellidae) to plants in forests and watersheds of the Hawaiian Islands. Environmental Entomology, 2000, Vol.29, No.2, pp.171-180, 20 ref.

Two-spotted leafhopper (generalist) -- AB: Experiments were performed to determine the role of the leafhopper S. rufofascia in the damage observed on forest and watershed plants in the Hawaiian Islands, USA. Laboratory manipulation of leafhopper populations on fiddlewood, Citharexylum spinosum , caused interveinal chlorosis and vein browning on young fully expanded leaves similar to that observed on leafhopper infested plants seen in the field and necrosis on older leaves. Field studies with caged "uluhe" fern, Dicranopteris linearis , conducted during 26 March-15 August 1997 in Oahu and during 7 July-12 December 1995 in Puhimau, Hawaii, demonstrated that frond veins turned brown within 2 days of leafhopper feeding; and by 141 days after feeding, an average of 85% of the surface area of the fronds were necrotic compared with only 12% necrosis in untreated cages. Field trials with stump-cut firetree, Myrica faya , were performed during 13 September 1995-22 February 1996 in Volcano, Hawaii to determine the eff

4.07

Little and Wadsworth. 1964. Common trees of Puerto Rico and the Virgin Islands. USDA Forest Service.

berries said to be sweet and edible

4.08

if thicks are formed, and trees are deciduous, it is possible

4.09

(1)Burke's Backyard Magzine (2000) Burke's Backyard Online, Fact sheet: Fiddlewood. <http://www.burkesbackyard.com.au/facts/2000/garden/fiddlewood_25.html> (2)http://hort.ifas.ufl.edu/shrubs/CITFRUA.PDF

(1)"Fiddlewoods prefer full sun but will tolerate some shade." (2)plant grows in part shade/part sun, The canopy on shade-grown plants becomes thin and irregular;

4.1

(1)Burke's Backyard Magzine (2000) Burke's Backyard Online, Fact sheet: Fiddlewood. <http://www.burkesbackyard.com.au/facts/2000/garden/fiddlewood_25.html> (2)http://hort.ifas.ufl.edu/shrubs/CITFRUA.PDF

(1) "They like a well drained soil enriched with organic matter." (2)Soil tolerances: acidic; alkaline; sand; loam; clay;Soil salt tolerances: moderate

4.11

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"A tree reaching a height of as much as 50 feet, bears no spines, and has smooth, quadrangular twigs. "

4.12

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"It forms crowded stands even in undisturbed habitats. "

5.01

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"A tree reaching a height of as much as 50 feet, bears no spines, and has smooth, quadrangular twigs. "

5.02

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

""This evergreen, medium-sized tree does not have the spines that its scientific name suggests. "

5.03

no evidence

5.04

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"A tree reaching a height of as much as 50 feet, bears no spines, and has smooth, quadrangular twigs. "

6.01

no evidence

6.02

Hawaiian Ecosystems at Risk Project (HEAR) (1999) Fiddlewood (Citharexylum spinosum): an alien plant report from HEAR (PDF) available at <http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf>

"produce seedlings in Hawaii"

6.03

no evidence

6.04

Tomlinson, P. B.; Fawcett, P. 1972. Dioecism in Citharexylum [fruticosum] (Verbenaceae). Journal of the Arnold Arboretum, , Vol.53, No.3, pp.386-389.

can be dioecious

6.05

no evidence

6.06

no evidence

6.07

R. Criley, UH Department of Horticulture, personal communication

7.01

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"Planted as a street tree." Dropped berries and seeds can stick to shoes

7.02

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

"Extensively planted as an ornamental. "

7.03

no evidence

7.04

no evidence

7.05

no evidence

7.06

(1)USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm> (2)http://miami-dade.ifas.ufl.edu/programs/fyn/publications/dtpl-shrubs-a-ci.htm

(1)fleshy berry (2)Attractive to birds

7.07

no evidence

7.08

dispersed by birds

8.01

USDA, Institute of Pacific Islands Forestry (2001) Pacific Island Ecosystems at Risk (PIER) webpage <http://www.hear.org/pier/phkar.htm>

(1) "The fruit is a shiny, black, oblong drupe less than 0.5 inch long" -- each inflorescence typically consistts of about 100 berries (2 nutlets per berry), so likely more than 1000 seeds / m2

8.02

Barbosa, J. M.; Santos Junior, N. A. dos; Pisciottano, W. A. 2000. Effect of burial and submersion on seed survival of native species used in riparian forestation. FT: Efeito do soterramento e da submersão sobre a sobrevivência de sementes de espécies nativas utilizadas em reflorestamentos ciliares. Revista Árvore, , Vol.24, No.3, pp.317-322

based on congener: "Citharexylum myrianthum seeds were not resistant to burial for more than 30 days"

8.03

no evidence

8.04

Hawaiian Ecosystems at Risk Project (HEAR) (1999) Fiddlewood (Citharexylum spinosum): an alien plant report from HEAR (PDF) available at <http://www.hear.org/species/reports/citspi_fskm_awwa_report.pdf>

"fiddlewood is able to grow back after being cut to the ground,"

8.05

Jones, V. P.; Anderson-Wong, P.; Follett, P. A.; Yang PingJun; Westcot, D. M.; Hu, J. S.; Ullman, D. E. (2000) Feeding damage of the introduced leafhopper Sophonia rufofascia (Homoptera: Cicadellidae) to plants in forests and watersheds of the Hawaiian Islands. Environmental Entomology, 2000, Vol.29, No.2, pp.171-180, 20 ref.

AB: Experiments were performed to determine the role of the leafhopper S. rufofascia in the damage observed on forest and watershed plants in the Hawaiian Islands, USA. Laboratory manipulation of leafhopper populations on fiddlewood, Citharexylum spinosum , caused interveinal chlorosis and vein browning on young fully expanded leaves similar to that observed on leafhopper infested plants seen in the field and necrosis on older leaves. Field studies with caged "uluhe" fern, Dicranopteris linearis , conducted during 26 March-15 August 1997 in Oahu and during 7 July-12 December 1995 in Puhimau, Hawaii, demonstrated that frond veins turned brown within 2 days of leafhopper feeding; and by 141 days after feeding, an average of 85% of the surface area of the fronds were necrotic compared with only 12% necrosis in untreated cages. Field trials with stump-cut firetree, Myrica faya , were performed during 13 September 1995-22 February 1996 in Volcano, Hawaii to determine the effect of leafhopper feeding on new growt