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

Dichorisandra thyrsiflora J. C. Mikan; blue ginger, blue spiral ginger

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

n

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

n

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

n

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

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

n

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

y

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

y

6.07

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

See left

2

7.01

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

y=1, n=-1

n

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

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

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:

1

Notes

Source

1.01

no evidence

1.02

on a list of plants found within Skukuza staff village [not naturalized]

http://www.parks-sa.co.za/conservation/scientific_services/Biota/villageplantspolicy.htm

1.03

no evidence

2.01

Native:
SOUTHERN AMERICA
Brazil: Brazil

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Dichorisandra+thyrsiflora (25 June 2004)

2.02

2.03

(1) Hardiness Range 8B to 11
(2) USDA: 10-12; Frost Tolerance: Tender in Phoenix, does not take any frost, should be kept inside in a bright location, or in a greenhouse (3)Watering Needs: Abundant water, keep soil moist

(1) Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.
(2) http://www.desert-tropicals.com/Plants/Commelinaceae/Dichorisandra_thyrsiflora.html (3)http://www.desert-tropicals.com/Plants/Commelinaceae/Dichorisandra_thyrsiflora.html

2.04

Native:
SOUTHERN AMERICA
Brazil: Brazil

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.
URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/tax_search.pl?Dichorisandra+thyrsiflora (25 June 2004)

2.05

(1) "widely grown for its dense, deep violet inflorescences", (2) New Zealand, (3) Hawaii, (4) Florida, Hawaii, Virginia

(1) Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp.
(2) http://www.doc.govt.nz/Publications/004~Science-and-Research/DOC-Science-Internal-Series/PDF/DSIS9.pdf
(3) Neal, M.C. (1965) In Gardens of Hawaii. Bernice p. Bishop Museum Special Publicatio 50. Bishop Museeum Press, Honolulu. 924pp. p.184
(4) http://plantsdatabase.com/go/1238/index.html

3.01

on a list of plants found within Skukuza staff village [not naturalized]

http://www.parks-sa.co.za/conservation/scientific_services/Biota/villageplantspolicy.htm

3.02

no evidence

3.03

no evidence

3.04

NOT on Australia garden thugs list

Randall, R. 2001. Garden thugs, a national list of invasive and potentially invasive garden plants. Plant Protection Quarterly 16:138-171.

3.05

no evidence

4.01

no desdcription of these traits

Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp. P177

4.02

no evidence

4.03

no evidence

4.04

no evidence

4.05

no evidence

4.06

no evidence

4.07

no evidence

4.08

Growth Habits: Evergreen perennial, Watering Needs: Abundant water, keep soil moist, the air should be humid when the plant is in growth [unlikely; evergreen herb grow in wet habitat]

http://www.desert-tropicals.com/Plants/Commelinaceae/Dichorisandra_thyrsiflora.html

4.09

(1)Exposure Partial shade or partial sun (2)Part shade

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.coyote-creek.net/herbs.html

4.1

(1)Soil Condition Loamy, acidic, neutral (2)Soil Requirements: Fertile, well-drained soil, Salt Tolerance: Low

(1)Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7. (2)http://www.floridagardener.com/pom/dichorisandra.htm

4.11

Herb, erect, to 2 m high

Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp. P177

4.12

no evidence

5.01

terrestrial

5.02

herb, Commelinaceae

5.03

Commelinaceae

5.04

Observation on the potato-like, food storage tubers

http://forums.gardenweb.com/forums/load/ginger/msg0112064421472.html

6.01

no evidence

6.02

propagate by cuttings, division, or seed

Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp. P177

6.03

no evidence

6.04

p.1229 "Dichrosandra are andromonoecious"

Hardy, Christopher R.; Stevenson, Dennis Wm. and Kiss, Helen G. (2000) Development of the gametophytes, flower, and floral vasculature in Dichorisandra thyrsiflora (Commelinaceae) American Journal of Botany 87:1228-1239.)

6.05

p.1231 "pollen is apparently released by the virbration induced by pollen-collecting bees as in many other buzz-pollinated flowers. Vibration mediated removal of pollen by bees of the genus Bombus has been observed for cultivated plants of D. thyrsiflora."

Hardy, Christopher R.; Stevenson, Dennis Wm. and Kiss, Helen G. (2000) Development of the gametophytes, flower, and floral vasculature in Dichorisandra thyrsiflora (Commelinaceae) American Journal of Botany 87:1228-1239.)

6.06

(1)Erect, clump-forming, rhizomatous (2)They root easily. Just cut pieces of the cane and stick in the ground. [plant of wet environments, spread by framentation along streams is likely]

(1)http://www.floridagardener.com/pom/dichorisandra.htm (2)http://davesgarden.com/pdb/go/1238/

6.07

(1)Rate of Growth: Medium (2)Rapid growth to 5'. [from seed, minimum estimate for herbaceous shady perennial]

(1)http://www.floridagardener.com/pom/dichorisandra.htm (2)http://www.maasnursery.com/flowerdatabase15.htm

7.01

no evidence

7.02

"widely grown for its dense, deep violet inflorescences"

Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.177

7.03

no evidence

7.04

"arilloid seeds"

Hardy, Christopher R.; Stevenson, Dennis Wm. and Kiss, Helen G. (2000) Development of the gametophytes, flower, and floral vasculature in Dichorisandra thyrsiflora (Commelinaceae) American Journal of Botany 87:1228-1239.)

7.05

no evidence

7.06

(1) "arilloid seeds"
(2) picture of fruit showing red color [bird-dispersal syndrome] (3)Fruits: Fleshy, orange-red

(1) Hardy, Christopher R.; Stevenson, Dennis Wm. and Kiss, Helen G. (2000) Development of the gametophytes, flower, and floral vasculature in Dichorisandra thyrsiflora (Commelinaceae) American Journal of Botany 87:1228-1239.)
(2) http://plantsdatabase.com/showimage/30177.html (3)http://www.floridagardener.com/pom/dichorisandra.htm

7.07

no evidence of attchment

7.08

(1) "arilloid seeds"
(2) picture of fruit showing red color [bird-dispersal syndrome] (3)Fruits: Fleshy, orange-red

(1) Hardy, Christopher R.; Stevenson, Dennis Wm. and Kiss, Helen G. (2000) Development of the gametophytes, flower, and floral vasculature in Dichorisandra thyrsiflora (Commelinaceae) American Journal of Botany 87:1228-1239.)
(2) http://plantsdatabase.com/showimage/30177.html (3)http://www.floridagardener.com/pom/dichorisandra.htm

8.01

(1) "fruit a obovate capsule" (2) arillate seeds [seeds must be relatively large to accommodate aril - few seeds per capsule]

(1)Whistler, A.W. (2000) Tropical Ornamentals: A Guide. Timber Press, Inc., Portland, Oregon. 542pp. p.177 (2)http://www.science.uts.edu.au/sasb/monocotsIIAb2.html

8.02

seeds germinate in 19 days [unlikely to form a seed bank]

http://theseedsite.co.uk/list11.html

8.03

no evidence

8.04

Root Form: rhizome [able to regenerate from rhizome]

Horticopia A-Z.Horticopia, Inc., Purcellville, VA. ISBN 1-887215-07-7.

8.05

no evidence