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

Cycas revoluta (King Sago Palm 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

1

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

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

y

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

y

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

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

y

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

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

15

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

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

8.05

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

y=-1, n=1

Total score:

-2

Notes

Source

1.01

No evidence

1.02

No evidence

1.03

No evidence

2.01

(1))the subtropical C. revoluta is native to the Far East (2)Distribution: Nansei Islands & Ryukyu Islands (Japan), South China (3)USDA hardiness zones: 8B through 11

(1)http://www.rhapisgardens.com/sagos/ (2)http://www.plantapalm.com/vce/species/cycas_revoluta.htm (3)http://hort.ifas.ufl.edu/shrubs/cycrev.pdf

2.02

[most of range is borderline subtropical / warm temperate]

2.03

(1)This subtropical adapts to a wide range of temperatures from 15 to 110 degrees F (-11 to 42 degrees C) (2)Widely distributed through the Ryukyu Islands of southern Japan, today primarily on steep to precipitous stony sites, but previously on flatter land now cleared. Reports of natural occurrences in coastal Fukien Province of China have not been substantiated, although circumstantial support for these claims is strong. [restricted native range, but occurs in cultivation under a broader range of tropical or subtropical environments]

(1)http://www.rhapisgardens.com/sagos/ (2)http://plantnet.rbgsyd.gov.au/cgi-bin/taxon.pl?name=Cycas+revoluta

2.04

(1)the subtropical C. revoluta is native to the Far East [borderline subtropics] (2)Distribution: Nansei Islands & Ryukyu Islands (Japan), South China

(1)http://www.rhapisgardens.com/sagos/ (2)http://www.plantapalm.com/vce/species/cycas_revoluta.htm

2.05

(1)Seattle (2)Florida (3)Hawaii

(1)http://www.botanik.uni-bonn.de/conifers/cy/cy/revoluta.htm (2)http://hort.ifas.ufl.edu/shrubs/cycrev.pdf (3)Neil, M.C. 1959. In Gardens of Hawaii.

3.01

No evidence

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

No evidence

4.01

No evidence

4.02

No evidence

4.03

No evidence

4.04

Our dogs, cats, cows, and horses have lived in and around our "Sago patches" for years and none have suffered ill effects, although we've seen cows munching on the leaves.

http://www.rhapisgardens.com/sagos/

4.05

(1)Animals that graze on Cycas leaves may exhibit permanent nuerological disorders. Cycas seed is sometimes suggested as a natural remedy for certain conditions - do not use it! All parts of this plant are toxic. (2)I've heard reports that some puppies who eat seed can get extremely sick. (3)Animals that graze on Cycas leaves may exhibit permanent nuerological disorders. Cycas seed is sometimes suggested as a natural remedy for certain conditions - do not use it! All parts of this plant are toxic. (4)Animal Poison Control Center > Clinical signs: vomiting, melena, icterus, increased thirst, hemorrhagic gastroenteritis, bruising, coagulopathy, liver damage, liver failure, death.(5)We are mourning the loss of one of our Jack Russell Terriers to eating a Sago Palm seed. Our house is very quiet and our other two Jack Russells miss their young friend. We had NO idea how poisonous Sago seeds are.

(1)http://www.floridata.com/ref/c/cyca_rev.cfm (2)http://www.rhapisgardens.com/sagos/ (3)http://www.floridata.com/ref/c/cyca_rev.cfm (4)http://www.aspca.org/site/PageServer?pagename=apcc (5)http://www.emilycompost.com/sago_palm1.htm

4.06

(1)This site lists 45 fungi species to be associated with Cycas revoluta. (2)Leaf-spotting diseases can be a major problem for King
Sago Palm. [not economic pest of other plants] (3)cycad scale (Aulacaspis yasumatsui) [specific to cycads]

(1)http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm (2)http://hort.ifas.ufl.edu/shrubs/cycrev.pdf (3)http://www.ronsympson.com/generic94.html

4.07

(1)Poisonous Part -Fleshy seeds, leaves, unprocessed flour from stem pith. Symptoms -Vomiting, diarrhea, headache, dizziness, seizures. Edibility -EDIBLE PARTS: Processed flour. Toxic Principle -Glycosides and an amino acid BMAA. Severity TOXIC ONLY IF LARGE QUANTITIES EATEN. (2)Seeds and stem starch have been widely used as a food source; a large plant may yield over 1,000 seeds. The Ryuku Islanders make a form of sake that is poisonous and an occasional batch kills all who partake (3)TOXICITY: The seed and plant parts of Cycas revoluta is not for consumption and is often confused with a true palm tree Mextroxylon, also called Sago Palm, which is used for food in tropical countries.

(1)http://www.ces.ncsu.edu/depts/hort/consumer/poison/Cycasre.htm (2)http://www.botanik.uni-bonn.de/conifers/cy/cy/revoluta.htm (3)http://www.rhapisgardens.com/sagos/

4.08

evergreen species.

http://www.rhapisgardens.com/sagos/

4.09

(1)LIGHT: Sagos grow in full sun, but adapt to outdoor shade or an indoor area which receives bright light or a few hours of morning or afternoon sun. (2)When given sufficient room to spread, King Sago performs very well in shade, part shade,

(1)http://www.rhapisgardens.com/sagos/ (2)http://hort.ifas.ufl.edu/shrubs/cycrev.pdf

4.1

(1)SOIL should be well drained and rich in humus, although these durable plants seem to grow in almost anything. (2)Soil tolerances: slightly alkaline; clay; sand; acidic; loam

(1)http://www.rhapisgardens.com/sagos/ (2)http://hort.ifas.ufl.edu/shrubs/cycrev.pdf

4.11

No evidence

4.12

No evidence

5.01

Cycadaceae

5.02

Cycadaceae

5.03

Strong fertilizers, fresh manure and the like are best avoided as they can damage the sago's coralloid roots (specialized structures that host blue-green algae that fix nitrogen from the air and make it available to the plant).

http://www.floridata.com/ref/c/cyca_rev.cfm

5.04

No evidence

6.01

In their native habit, Cycads are pollinated by wind or insects, however, in cultivation, they usually must be hand-pollinated for viable seed production. ...Sometimes, wind, bees, or insects can pollinate the plants.

(1)http://www.rhapisgardens.com/sagos/ (2)http://www.rhapisgardens.com/sagos/sagoseed.htm

6.02

In late spring, a mature male Sago produces a golden cone, shaped like a giant pine cone which may grow over 2' tall as shown in the photo above. A female, shown below, produces a huge golden flower which slowly opens when it is fertile, then closes, and begins to produce viable seed if pollination from a male sago was successful.

http://www.rhapisgardens.com/sagos/

6.03

SHOGUN' CYCAS TAITUNGENSIS X REVOLUTA hybrid by Chumley [artificial hybrid]

http://cycadsales.com/aboutme.html

6.04

Dioecious species - separate male and female plants.

(1)http://www.rhapisgardens.com/sagos/ (2)http://www.rhapisgardens.com/sagos/sagoseed.htm

6.05

(1)In their native habit, Cycads are pollinated by wind or insects, however, in cultivation, they usually must be hand-pollinated for viable seed production. ...Sometimes, wind, bees, or insects can pollinate the plants. (2)In the wild this can occur by wind dispersion of male pollen but it is believed that most of the pollination is done by native insects.

(1)http://www.rhapisgardens.com/sagos/ and http://www.rhapisgardens.com/sagos/sagoseed.htm (2)http://www.junglemusic.net/cycadadvice/cycads-sago-palm.htm

6.06

Offsets growing around the base should be removed with a sharp knife or trowel. [Suckers do not naturally fragment in the wild].

http://www.plantoftheweek.org/week199.shtml

6.07

(1)Most Sagos must be at least 15 -20 years old before they are mature enough to bloom. (2)The palms might be 15 years before they bloom.

(1)http://www.rhapisgardens.com/sagos/sagoseed.htm (2)http://www.desert-tropicals.com/Plants/Cycadaceae/Cycas_revoluta.html

7.01

no evidence that the propagules have any means of attachemnt. 'Best kept away from paths, since the leaves are quite spiky. '

http://www.pacsoa.org.au/cycads/Cycas/revoluta.html

7.02

(1)Cycas revoluta, one of the most primitive living seed plants, are very unusual and popular ornamentals. (2)This is the most popular and widely cultivated of the cycads. It makes an excellent landscape plant, as well being very well suited to pot culture, and even bonsai (see Bonsai Cycads).

(1)http://www.rhapisgardens.com/sagos/ (2)http://www.pacsoa.org.au/cycads/Cycas/revoluta.html

7.03

relatively large seeds.

(1)http://www.pacsoa.org.au/cycads/Cycas/revoluta.html (2)http://www.botanik.uni-bonn.de/conifers/cy/cy/revoluta.htm

7.04

relativaely large seeds - no evidence that propagules have adaptation for wind dispersal.

7.05

The seeds of cycas are quite great, and normally they have showy colors: red, purple and yellows are common. These colored seeds appear in the mature cones of cycas, the fruitful organs are born separated of others, the alive colors attract the birds and a great variety of mammals, that gratuitously take care to disperse the seeds.

http://translate.google.com/translate?hl=en&sl=es&u=
http://barrioperu.terra.com.pe/pepemelgarejo/&prev=/search%
3Fq%3DCycas%2Brevoluta%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DG

7.06

The seeds of cycas are quite great, and normally they have showy colors: red, purple and yellows are common. These colored seeds appear in the mature cones of cycas, the fruitful organs are born separated of others, the alive colors attract the birds and a great variety of mammals, that gratuitously take care to disperse the seeds.

http://translate.google.com/translate?hl=en&sl=es&u=
http://barrioperu.terra.com.pe/pepemelgarejo/&prev=/search%
3Fq%3DCycas%2Brevoluta%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DG

7.07

No evidence that propagules have any means of attachment.

http://translate.google.com/translate?hl=en&sl=es&u=
http://barrioperu.terra.com.pe/pepemelgarejo/&prev=/search%
3Fq%3DCycas%2Brevoluta%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sa%3DG

7.08

Probably yes - 'The seeds of cycas are quite great, and normally they have showy colors: red, purple and yellows are common. These colored seeds appear in the mature cones of cycas, the fruitful organs are born separated of others, the alive colors attract the birds and a great variety of mammals, that gratuitously take care to disperse the seeds.'

8.01

(1) relatively large seeds. Seeds are brownish-red, the shape of a flattened marble, about 30 mm( 1.25 ins) across. (2)a large plant may yield over 1,000 seeds

(1)http://www.pacsoa.org.au/cycads/Cycas/revoluta.html (2)http://www.botanik.uni-bonn.de/conifers/cy/cy/revoluta.htm

8.02

(1)If you don't plan to plant the seed right away, store in a cool, dry place. Before planting, soak in a bucket of water for a day to remoisturize the hard ivory seed coat. Seed can be stored for up to several months. (2)cycad seeds have no dormancy

(1)http://www.rhapisgardens.com/sagos/sagoseed.htm (2)http://plantnet.rbgsyd.gov.au/PlantNet/cycad/cycsour.html

8.03

No evidence that the species is being controlled for.

8.04

Never prune more than 1/3 of any plant material; Removing more of the sago will not regenerate itself

8.05

Don’t know