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

Chorisia speciosa (floss-silk 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

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

y

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

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

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

n

6.05

Requires specialist pollinators

y=-1, n=0

y

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

5

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

y

7.05

Propagules water dispersed

y=1, n=-1

n

7.06

Propagules bird dispersed

y=1, n=-1

n

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

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

n

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

No evidence

1.03

No evidence

2.01

(1)Origin Brazil. (2)Native of Brazil and Argentina.

(1)http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html (2)http://www.botgard.ucla.edu/html/MEMBGNewsletter/Volume2number1/Bombacaceae.html

2.02

2.03

USDA zones 9b to 10.

http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html

2.04

(1)Origin Brazil. (2)Native of Brazil and Argentina.

(1)http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html (2)http://www.botgard.ucla.edu/html/MEMBGNewsletter/Volume2number1/Bombacaceae.html

2.05

(1) 'A native of South America but is is grown in tropics and mild subtropics in many parts of the world mainly for is beautiful flowers.' (2)Introduced to Arizona in U.S. (3)Introduced to Florida.

(1)Bose, T.K., Das, p. and Maiti, G.G. 1998, Trees of the world. Regional plant resource center. India. (2)Smith, R.C. 1986. Chorisia speciosa. American Nurseryman. 163(6): 200. (3)http://mgonline.com/chorisia.html

3.01

No evidence

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

The picture shows spines all over the mature tree trunk (1) as well as on seedling (2). (3) '...the trunk studded with persistent, stout, gray "spines." Botanically speaking, these sharp projections are termed trunk prickles, bark prickles, or stem emergences--that is, outgrowths from internal stem tissues.'

(1)http://www.cuyamaca.net/oh170/Thumbnail_Pages/Chorisia_speciosa.asp (2)http://pictures.bonsaitalk.com/showphoto.php?photo=167 (3)http://www.botgard.ucla.edu/html/MEMBGNewsletter/Volume2number1/Bombacaceae.html

4.02

No evidence

4.03

No evidence

4.04

Don’t know

4.05

No evidence

4.06

Botryosphaeria ribis: India - 8189
Camillea campinensis: Brazil - 6601, 34636
Cercospora chorisiae: Japan - 7010
Colletotrichum sp.: FL - 1
Corynespora sp.: FL - 1
Fusarium semitectum: FL - 6740
Macrophoma sp.: FL - 1
Phyllactinia chlorisiae: Brazil - 6601
Phyllactinia chorisiae: Brazil - 7190, 34636
Phyllosticta sp.: FL - 1
Phyllosticta sp : FL - 1, 1
No evidence that the above pathogens are recognized pests.

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

4.07

No evidence

4.08

Young trunks are green, [single trunk large tree

http://www.sheridangardens.com/Trees/thetrees_30to40ft.htm

4.09

Exposure: full sun.
(3) S. granuloso-leprosum , Chronisia speciosa , Piptadenia gonoacantha , F. guaranitica , T. micrantha , and Schizolobium parahyba were the most shade intolerant. These latter species showed little or no survival under the shade conditions

(1)http://www.cuyamaca.net/oh170/Characteristic%20Pages/Chorisia%20speciosa.asp (2)http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html
(3) Souza, R. P. de; Válio, I. F. M. (2001) Seed size, seed germination, and seedling survival of Brazilian tropical tree species differing in successional status. Biotropica, 2001, Vol.33, No.3, pp.447-457, 39 ref.

4.1

(1) 'Floss Silk is happy in most soils with good drainage …' (2)Soil pH requirements:
5.1 to 5.5 (strongly acidic)
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)

(1)http://dsp-159.innerhost.com/mgonline/Chorisia/Chorisia.html (2)http://plantsdatabase.com/go/53598/

4.11

Not a vine.

http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html

4.12

No evidence

5.01

A 25 to 75 ft tall tree in Bombacaceae.

http://www.cuyamaca.net/oh170/Characteristic%20Pages/Chorisia%20speciosa.asp

5.02

5.03

5.04

6.01

Produces flowers and seeds.

http://translate.google.com/translate?hl=en&sl=es&u=http://
www.floraguide.es/arboles/Chorisiaspeciosa.htm&prev=/search%3Fq%3D
Chorisia%2Bspeciosa%26start%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DN

6.02

(1) 'The seeds are seeded directly, without previous treatments, and germinate with facility.' (2)Photo of seedling raised from seed. (3) 'As part of a larger study evaluating several silvicultural techniques for restoring tropical moist forests on abandoned agricultural lands in southeastern Brazil, direct seeding with five early-successional Atlantic forest species was tested at three degraded sites, characterized by different soil types and land-use histories, within the Environmental Protection Area at Botucatu, SP. The species used in this study were Chorisia speciosa, Croton floribundus, Enterolobium contorstisiliquum, Mimosa scabrella, and Schizolobium parahyba. Scarified seeds of each of these species were sown in prepared seed spots in replicated, 0.25 ha mixed-species plots at an initial espacement of 1 mX1 m at each site. Of the five species planted, only two, Enterolobium and Schizolobium, showed good seed germination, seedling survival, and early growth rates, averaging 4.1-4.6 cm stem diameter

(1) http://translate.google.com/translate?hl=en&sl=es&u=http://
www.floraguide.es/arboles/Chorisiaspeciosa.htm&prev=/search%3Fq%3D
Chorisia%2Bspeciosa%26start%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DN (2)http://pictures.bonsaitalk.com/showphoto.php?photo=167 (3)Engel-Vera-Lex; Parrotta-John-A. 2001.An evaluation of direct seeding for reforestation of degraded lands in central Sao Paulo state, Brazil. Forest-Ecology-and-Management. [print] 15 October, 2001; 152 (1-3): 169-181.

6.03

'The ornamental F1 hybrid Chorisia x insigniosa , obtained from the cross C. insignis x C. speciosa , and the Hippeastrum hybrid Smriti Narain, derived from the cross between cultivars Charm and Orthelo, are briefly described. ' -[ No evidence of natural hybridization.]

New hybrids.
India, National Botanical Research Institute, Lucknow - 226 001, India. NBRI Newsletter, 1995, Vol.22, No.1, pp.4-5

6.04

"4 neotropical woody species (Chorisia chodatii , C. speciosa , Tabebuia caraiba [Tecoma caraiba ] and T. ochracea ) from 2 phylogenetically distinct families for which previous studies had indicated late-acting self-incompatibility (SI)."

Gibbs, P. E.; Bianchi, M.. 1993. Post-pollination events in species of Chorisia (Bombacaceae) and Tabebuia (Bignoniaceae) with late-acting self-incompatibility. Botanica Acta. Vol.106, No.1, pp.64-71, 22 ref.

6.05

(1) 'The features of large size, thick parts to avoid mechanical damage, and copious pollen indicate that bats would be appropriate pollinators for these trees in their natural habitats.'

(1)http://www.botgard.ucla.edu/html/MEMBGNewsletter/Volume2number1/Bombacaceae.html

6.06

Propagation by seed.

http://www.desert-tropicals.com/Plants/Bombacaceae/Chorisia_speciosa.html

6.07

'It grows reasonably fast and flowering starts in 5 -6 years after planting of seedling.'

Bose, T.K., Das, p. and Maiti, G.G. 1998, Trees of the world. Regional plant resource center. India.

7.01

Probably not - no evidence that the seeds have any means of attachment.

7.02

Probably yes - an ornamental tree.

http://www.cuyamaca.net/oh170/Characteristic%20Pages/Chorisia%20speciosa.asp

7.03

Probably not - seeds relatively large - 10mm long to about 8 mm broad.

Pereira-De-Souza-Rogeria {a}; Valio-I-F-M. 2001.Seed size, seed germination, and seedling survival of Brazilian tropical tree species differing in successional status. Biotropica. 33(3): 447

7.04

'At maturity, five valves of the capsule fall away (the fruit is dehiscent) to reveal the locules, now filled with five elongate masses of silky white hairs. Floss-silk resembles cotton but, unlike cotton, is attached just below the seeds, which are hidden by the silk. When released, these silky hairs help to disperse the seeds in strong winds in the canopy, ...'

http://www.botgard.ucla.edu/html/MEMBGNewsletter/Volume2number1/Bombacaceae.html

7.05

7.06

7.07

7.08

no evidence that it is consumed

8.01

Probably not - seeds relatively large - 10mm long to about 8 mm broad. [but released in masses]

Pereira-De-Souza-Rogeria {a}; Valio-I-F-M. 2001.Seed size, seed germination, and seedling survival of Brazilian tropical tree species differing in successional status. Biotropica. 33(3): 447

8.02

AB: "Chorisia speciosa, Croton floribundus and Citharexylum myrianthum seeds were not resistant to burial for more than 30 days. "

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, 2000, Vol.24, No.3, pp.317-322, 21 ref.

8.03

No information that the species is being controlled for.

8.04

(1) 'Tolerates light pruning when necessary. '
(2) 'Nature, in its own style has often done just such severe pruning of Chorisia trees here in northern California. They will send out new branches from the main trunk if topped, as you suggest, but the cuts are very prone to rot as previously mentioned. I'd suggest a cut on the diagonal as being more desirable esthetically, with new branching above the cut, it can still look good from one side as it regrows.'

(1)http://www.lebonjardinier.com/chorisia%20speciosa.htm (2)http://www.raingardens.com/bbs/index.cgi?read=3038

8.05

Don’t know.