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

Dracaena draco (dragon tree, kite tree)

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

1

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

n

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

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

n

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

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

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

y

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

10

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

n

8.05

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

y=-1, n=1

Total score:

-5

Source

Notes

1.01

No evidence

1.02

No evidence of naturalization.

1.03

No evidence

2.01

While the Dragon Tree is endemic to Canary Islands, Madeira & Cape Verde, only a few individuals can be found growing naturally, and these are mainly on the islands of Tenerife and La Palma, growing in dry bush at the low elevations of the islands' rocky mountain ranges.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

2.02

2.03

(1) USDA zone 10 (2)USDA: 9b-12 (3)plants of the upper parts of the lower xerophytic zone [native range]

(1)horticopia plant master, cd-rom database (2)http://www.desert-tropicals.com/Plants/Agavaceae/Dracaena_draco.html (3)Hueppe-J; Pott-R; Wildpret-De-La-Torre-W 1996. Environmental differentiation within the subtropical xerophytic scrub zone of the Canary Island of Tenerife.Phytocoenologia- 26 : 417-44

2.04

(1)While the Dragon Tree is endemic to Canary Islands, Madeira & Cape Verde, only a few individuals can be found growing naturally, and these are mainly on the islands of Tenerife and La Palma, growing in dry bush at the low elevations of the islands' rocky mountain ranges. (2)Dracaena draco is known from the islands of Sto. Antão, S. Vicente, S. Nicolau, Santiago, Fogo and Brava. In the Red Data Book of Cape Verde Dracaena draco is classified as "Endangered". It is extinct on Brava and Santiago where only planted specimen are known today and in severe risk of extinction on the island of S. Vicente (classified Critically Endangered).

(1)http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html (2)http://www.plant-talk.org/trees/dracdrac.html

2.05

(1)Bermuda (2)Australia (3)Arizona (4)San diego (5)South Africa

(1)http://bermuda-online.org/flowers.htm (2)http://www.growinglifestyle.com/ad/new/a52845.html (3)http://www.desert-tropicals.com/Plants/Agavaceae/Dracaena_draco.html (4)http://www.admin.is.sandiego.edu/fmgmt/plants.asp (5)http://www.rnzih.org.nz/pages/review1.htm

3.01

No evidence of naturalization.

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

No evidence

horticopia plant master, cd-rom database

4.02

No evidence

4.03

No evidence

4.04

No information.

4.05

(1)toxic to pets (2)safe plant for pet birds [contradicts latter reference]

(1)http://www.dublinvet.com/petinfo/toxicplants.htm (2)http://www.multiscope.com/hotspot/safeplants.htm

4.06

This site lists 30 fungi to be associated with D. draco [no serious non-generalis pests of agriculture]

http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm

4.07

low risk of poisoning children and may be considered for use in the home

http://www.safekid.org/plants.htm

4.08

Unlikely based on morphology, evergreen tree with large leaves but relatively low leaf are per tree.

4.09

(1)sun: full (2)prefers dry sunny spots. (3)Full sun or light shade

(1)horticopia plant master, cd-rom database (2)http://www.fernsgarden.co.nz/stories/storyReader$234 (3)http://www.desert-tropicals.com/Plants/Agavaceae/Dracaena_draco.html

4.1

soil type: sandy clay loam rocky unparticular

horticopia plant master, cd-rom database

4.11

type: upright tree

horticopia plant master, cd-rom database

4.12

No evidence

5.01

type: upright tree

horticopia plant master, cd-rom database

5.02

type: upright tree

horticopia plant master, cd-rom database

5.03

type: upright tree

5.04

type: upright tree

6.01

Dracaenas reproduce seeds in their native range but due to extinction of the birds that disperse the seeds, the species is facing extinction too.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

6.02

The results of the germination of Dracaena draco, of the seedlings and the plants survival in greenhouse and in garden, respectively, are presented. The results indicate that it is possible the propagation by seed in culture. This work is part of large program that pretends the re-introduction of this species in situ.

Monteiro-Ana {a}; Vasconcelos-Teresa {a}; Bertelli-Antonio-Tapada. 1999. Seed propagation of Dracaena draco L. Garcia-De-Orta-Serie-de-Botanica. 14 (2): 187-189.

6.03

No information regarding hybridization.

6.04

since they are forced to self-pollinate on account of their isolation, progenies are homozygous, too.

LEIBENGUTH-F 1985. ENZYME POLYMORPHISMS IN THE PHYLOGENETIC RELICS CYCAS-RUMPHII AND DRACAENA-DRACO. Biochemie-und-Physiologie-der-Pflanzen-BPP 180 : 465-471

6.05

Unlikely based on morphology -- fragrant, creamy-white flowers [small, open flowers]

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

6.06

Propagation by seed and cuttings. But no evidence of reproduction by vegetative means in the wild.

http://translate.google.com/translate?hl=en&sl=de&u=http://
www.pflanzen.onlinehome.de/zimmer/drachenbaum.htm&
prev=/search%3Fq%3DDracaena%2Bdraco%26hl%3Den%26lr%3D%26sa%3DG

6.07

Extremely slow growing, usually taking approximately 10 years to reach about 2-3ft. before its first flowering.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

7.01

Propagules do not have any means of attachment.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

7.02

Probably yes - 'Dracaenas are grown for their strap-shaped foliage which is colorfully striped in many of the cultivars.'

http://hgic.clemson.edu/factsheets/HGIC1504.htm

7.03

No produce

7.04

Seeds were dispersed by birds.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

7.05

Seeds were dispersed by birds.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

7.06

(1)Seeds were dispersed by birds. (2)orange berries

(1)http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html (2)http://www.desert-tropicals.com/Plants/Agavaceae/Dracaena_draco.html

7.07

Seeds were dispersed by birds.

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

7.08

'...Dragon Tree fruits were the main food of an endemic, Dodo-like, flightless bird which is now extinct. Related to the pigeon, it was about the size of a turkey. Because of the extinction of the species, naturally occurring Dragon Trees are becoming very rare. The processing of Dragon Tree seeds through the digestive tract of this bird helped stimulate germination - without this aid, seed must be manually processed in order to sprout.'

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

8.01

(1)One ovule per locule (2) Three lucules (cells) per berry [unlikely to produce 1000 per m2 , this is a large tree]

(1)Mabberley, D.J. 1998. The plant book. Cambridge University Press. (2)Wagner et al. 1999. Manual of Flowering Plants of Hawai‘I. University of Hawai‘i press, Honolulu

8.02

No information on seed longevity.

8.03

No evidence that the species is being controlled for.

8.04

Unlikely, it is a very slow growing tree (2-3 feed in 10 years)

http://www.mediterraneangardensociety.org/plants/Dracaena.draco.html

8.05

Don’t know.