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

Brahea armata S. Watson (blue hesper palm, blue fan palm, Mexican Blue Palm) Synonymy: Erythea armata, E. glauca, E. roezlii

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

y

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

y

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

y

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

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

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

y

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

8.05

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

y=-1, n=1

Total score:

3

Notes

Source

1.01

No evidence

1.02

No evidence

1.03

No evidence

2.01

(1)Distribution: Baja California (2)Origin: Mexico (3)Occurs naturally in Baja California and the Sonoran Desert of northwestern Mexico, where is grows in canyons (where water is available) from sea level to 5200 feet in elevation.

(1)http://www.plantapalm.com/vpe/photos/Species/brahea_armata.htm (2)http://www.plantapalm.com/vpe/photos/rosedownmill/brahea_armata-rdm.htm (3)Riffle, L. R. and Craft, P. 2003. An Encyclopedia of Cultivated Palms. Timber Press. Portland. U.S.A.

2.02

2.03

(1)USDA: 8b-10. Frost Tolerance: 10°F (-12°C) (2) It can tolerate freezes down to about -10C (possible lower for short spells) as long as it is kept in very well-drained soil. (3)grows in canyons (where water is available) from sea level to 5200 feet in elevation.

(1)http://www.desert-tropicals.com/Plants/Arecaceae/Brahea_armata.html (2)http://www.plantapalm.com/vpe/photos/rosedownmill/brahea_armata-rdm.htm (3)Riffle, L. R. and Craft, P. 2003. An Encyclopedia of Cultivated Palms. Timber Press. Portland. U.S.A.

2.04

(1)Distribution: Baja California (2)Origin: Mexico

(1)http://www.plantapalm.com/vpe/photos/Species/brahea_armata.htm (2)http://www.plantapalm.com/vpe/photos/rosedownmill/brahea_armata-rdm.htm

2.05

(1)The Mexican Blue is often seen throughout the Caribbean in premier hotels, like the Hyatt’s as a specimen plant. (2)Rarely seen in the tropics and sub-tropics, since it is usually too wet, and humid for them. (3)Florida (4)Australia

(1)http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm (2)http://www.pacsoa.org.au/palms/Brahea/armata.html (3)http://www.floridata.com/ref/B/brah_arm.cfm (4)http://www.etsautilities.com.au/pdf/fact_sheets/ets0105_tree_list_facts.pdf

3.01

No evidence

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

(1)The leaf stems are of medium length and have small thorns along the lower regions. (2)Rather spiny (3)armata = armed (spiny);

(1)http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm (2)http://www.palmdoctor.com/Palm_0f_The_Month/Brahea_armata.htm (3)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata

4.02

No evidence

4.03

No evidence

4.04

Probably not accessible by grazers - A tall palm.

http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata

4.05

No evidence

4.06

(2) "Damage: Severely attacked palm trees show a total loss of the palms and rotting of the trunk which lead to the death of the tree. Adult females lay eggs in the crown of palm trees, larvae then penetrate the crown and later to most parts of the upper trunk, making tunnels of up to 1 m long. Pupation takes place in a cocoon under the bark.
Pathway: Plants for planting of Palmae (including date palm, ornamental palms) from infested countries.
Possible risks: Date palms is an important crop in north African countries and ornamental palms are widely planted as amenity trees in the whole Mediterranean area."
[Rhynchophorus ferrugineus is a specialist pest of concern]

(1) Barranco, P. , Peña, J. A. de la , Martín, M. M. , Cabello, T. (2000) Host rank for Rhynchophorus ferrugineus (Olivier, 1790) and host diameter. (Coleoptera: Curculionidae). Boletín de Sanidad Vegetal, Plagas, 2000, Vol. 26, No. 1, pp. 73-78, 10 ref.
(2) http://www.eppo.org/QUARANTINE/Alert_List/insects/rhycfe.htm

4.07

(1)Round edible brown fruits, 0.8 inch in diameter (2 cm). (2)Although we have seen no reports of edibility, the fruit is almost certainly edible either raw or cooked[K]. It is about 2cm in diameter[200].
(3) the pollen was listed as low allergen in this report

(3) http://www.unce.unr.edu/publications/SpecPubs/SP0028.doc

4.08

(1)Habitat: Dry woodlands, usually on limestone soils. Evergreen palm. (2)fire retardant plant but only if dead leaves are intentionally removed [NOT as self-cleaning palm, so likely to be a fire hazard in natural ecosystems] (3)If old leaves are not removed, they form a continuous brown skirt, reaching from the top of the trunk all the way to the ground

(1)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata (2)http://www.clwa.org/fire_retardant_water_wise_plants.htm (3)http://www.floridata.com/ref/B/brah_arm.cfm

4.09

(1)Requirements: Full sun. Excellent drainage. (2)Sun Requirements: Full sun. Despises shade with moisture. (3)Sun Exposure: Full sun (4) It cannot grow in the shade.

(1)http://www.plantapalm.com/vpe/photos/rosedownmill/brahea_armata-rdm.htm (2)http://www.junglemusic.net/palms/brahea-armata.htm (3)http://www.desert-tropicals.com/Plants/Arecaceae/Brahea_armata.html (4)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata

4.1

(1)The plant prefers light (sandy), medium (loamy) and heavy (clay) soils, requires well-drained soil and can grow in nutritionally poor soil. The plant prefers acid, neutral and basic (alkaline) soils. (2)Soil requirements: Somewhat dry, sandy soil and good drainage. (30Blue hesper palm succeeds admirably in a wide range of soils in subtropical climates.

(1)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata (2)http://www.junglemusic.net/palms/brahea-armata.htm (3)http://www.floridata.com/ref/B/brah_arm.cfm

4.11

No evidence

4.12

No evidence

5.01

Arecaceae

5.02

Arecaceae

5.03

Arecaceae

5.04

An evergreen tree growing to 12m by 4m at a slow rate

http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata

6.01

No evidence

6.02

The seeds of Brahea Armata are about 1.5 cm in diameter, round in shape and germinate erratically, in anywhere from 1 to 12 months

http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm

6.03

No evidence

6.04

(1)Flower: hermaphoditic. (2)The flowers are hermaphrodite (have both male and female organs).

(1)http://www.desert-tropicals.com/Palm/Brahea_armata.html (2)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata

6.05

Typical arecaceae flowers [insect / bee]

6.06

No evidence

6.07

(1)Blue hesper palms may bloom at exceptionally early ages (2) Growth Rate: Slow (3) Growth rate: Slow [minimum estimate for an early-flowering slow growing large palm]

(1)http://www.floridata.com/ref/B/brah_arm.cfm (2)http://www.thegoodearthnursery.com/palm.htm (3)http://www.jurassicpalms.com/mexicanblue.html

7.01

relatively large seeds.(1) 'The seeds of Brahea Armata are about 1.5 cm in diameter, round in shape and germinate erratically, in anywhere from 1 to 12 months.' (2)Round edible brown fruits, 0.8 inch in diameter (2 cm

(1)http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm (2)http://www.desert-tropicals.com/Plants/Arecaceae/Brahea_armata.html

7.02

Ornamental palm.

http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl?Brahea+armata

7.03

relatively large seeds.(1) 'The seeds of Brahea Armata are about 1.5 cm in diameter, round in shape and germinate erratically, in anywhere from 1 to 12 months.' (2)Round edible brown fruits, 0.8 inch in diameter (2 cm

(1)http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm (2)http://www.desert-tropicals.com/Plants/Arecaceae/Brahea_armata.html

7.04

Fruit Composition: Fleshy

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

7.05

Found in dry habitats

7.06

Attractive fruit; Fruit Composition: Fleshy

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

7.07

No evidence [caching by rats?]

7.08

Bird dispersal

8.01

[this palm has massive inflorescences and seed clusters - 500+ seeds per cluster based on photos]

(http://www.pacsoa.org.au/palms/Brahea/armata.html

8.02

(1)Several years old seed will grow perfectly well. (2)Germination of fresh seed usually takes place in 3 - 4 months at 25°c[138]. Stored seed is very slow to germinate. [conflicting, results are for controlled storage] (3)Seeds are considered to have maximum viability if sown within 8-16 weeks after maturing. However, some blue hesper palm seeds are reported to germinate very easily, even after three years.

(1)http://www.tropicscentre.com/frame.htm?http://www.tropicscentre.com/encyc/palms/brah-arm/brah-arm.htm (2)http://www.comp.leeds.ac.uk/cgi-bin/pfaf/arr_html?Brahea+armata (3)http://www.floridata.com/ref/B/brah_arm.cfm

8.03

No evidence that the species is being controlled for;

8.04

no information on fire tolerance, but is probably adaptated to survive fire because it occurs naturally in fire-prone habitats

8.05

Don’t know