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

Euphorbia pulcherrima; Poinsettia pulcherrima, poinsettia, Christmas flower

Answer

1.01

Is the species highly domesticated?

y=-3, n=0

y

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

y

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

y

4.05

Toxic to animals

y=1, n=0

y

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

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

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

n

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

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

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

n

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

y

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:

-7

Notes

Source

1.01

Long before the arrival of Europeans, the Aztecs of central Mexico cultivated the plant and called it Cuetlaxochitl. Because of its brilliant color. With the introduction of the cultivar Paul Mikkelsen in 1963 (Fig. 5), poinsettias entered a new era. This cultivar, with stiff stems and foliage retention characteristics, provided the trade with the first longer-lasting cultivar of commercial importance. Annette Heggä Red was introduced in Norway in 1964. This cultivar was quickly followed by a number of sports. The Hegg cultivars introduced an entirely new type of multi-flowered plant to the trade because of their ability to produce from five to eight blooms from a pinch, and because of their ease of production.

1.02

No evidence of naturalization.

1.03

No evidence

2.01

Poinsettia is native to the tropical areas of Central America and Mexico.

http://www.floridata.com/ref/E/euph_pul.cfm

2.02

They are now grown and enjoyed nearly world-wide wherever Christmas is celebrated.

http://www.floridata.com/ref/E/euph_pul.cfm

2.03

(1)Hardiness range 9A- 10B. (2)originated in a rather limited region near present day Taxco

(1)http://www.hortpix.com/pc1780.htm (2)http://www.apsnet.org/online/feature/xmasflower/

2.04

Poinsettia is native to the tropical areas of Central America and Mexico.

http://www.floridata.com/ref/E/euph_pul.cfm

2.05

They are now grown and enjoyed nearly world-wide wherever Christmas is celebrated.

http://www.floridata.com/ref/E/euph_pul.cfm

3.01

No evidence of naturalization.

3.02

No evidence

3.03

No evidence

3.04

No evidence

3.05

E. helioscopia, E. heterophylla and E. hirta are listed as principal weed in several countries.

Holm et al. 1997. An electronic atlas of weeds and invasive species. Version1. CD-ROM database.

4.01

No evidence

http://www.floridata.com/ref/E/euph_pul.cfm

4.02

No evidence

4.03

No evidence

4.04

'Euphorbia species generally are highly unpalatable, but animals may eat them due to lack of good forage. Drying does not destroy the toxicity of the plant, and Euphorbia in hay may be slightly more palatable to livestock.'

http://www.library.uiuc.edu/vex/toxic/crown/crown2.htm

4.05

(1) 'Euphorbia species generally are highly unpalatable, but animals may eat them due to lack of good forage. Drying does not destroy the toxicity of the plant, and Euphorbia in hay may be slightly more palatable to livestock.' (2)Atleast 2 cases of poisoning have been recorded in connection with E. pulcherrima, the well known indoor plant poinsettia. In 1919 the 2 year old son of an army officer at Fort Shafter, Hawaii died after eating a few leaves. In Switzerland a dachshand died after also eating a few leaves. ... A post mortem revealed extensive accumulation of fluids in the lungs and stomach with congestion of internal organs. Death followed circulatory failure.

(1)http://www.library.uiuc.edu/vex/toxic/crown/crown2.htm (2)Turner, R. Euphorbias. A Gardners Guide.

4.06

(1) There are 92 species of fungi listed to be associated with this species.
(2) AB: The bionomics of Opogona sacchari and its control were studied in Beijing, China in 1995-96. It is stated that this was the first record of O. sacchari in China. The pest was found infesting Dracaena fragrans . It had 3-4 generations a year in Beijing and overwintered as larvae in soil near the roots of host plants cultivated in pots in greenhouses. Damage was most serious on wood segments of D. fragrans more than 3 years old. Seriously damaged plants had more than 50 heads of larvae on 1 m long wood segments. The insect also infests Euphorbia pulcherrima and Rhapis excelsa . Spraying 80% dichlorvos diluted at 1:1000, followed by wrapping with plastic film, or broadcast application of trichlorfon diluted at 1:200 gave good control of the insect. [also a important pest on palms]
(3) Amphobotrys ricini is also a pathogen of Ricinus communis
(4) AB: The disease reported from Florida comprises a new host record. In pathogenic

(1) http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm
(2) Cheng GuiFang; Yang JiKun (1997) Opogona sacchari (Bojer) - an important pest insect on Dracaena fragrans . Plant Protection, 1997, Vol.23, No.1, pp.33-35, 1 ref.
(3) Holcomb, G. E.; Brown, W. L. (1989) Basal stem rot of cultivated poinsettia caused by Amphobotrys ricini. Plant Disease, 1990, Vol.74, No.10, p.828, 2 ref.
(4) Chase, A. R. (1985) Bacterial leaf spot of Codiaeum variegatum cultivars caused by Xanthomonas campestris pv. poinsettiicola. Plant Pathology, 1985, Vol.34, No.3, pp.446-448, 5 ref.

4.07

(1) 'Euphorbia species generally are highly unpalatable, but animals may eat them due to lack of good forage. Drying does not destroy the toxicity of the plant, and Euphorbia in hay may be slightly more palatable to livestock.' (2)Atleast 2 cases of poisoning have been recorded in connection with E. pulcherrima, the well known indoor plant poinsettia. In 1919 the 2 year old son of an army officer at Fort Shafter, Hawaii died after eating a few leaves. In Switzerland a dachshand died after also eating a few leaves. ... A post mortem revealed extensive accumulation of fluids in the lungs and stomach with congestion of internal organs. Death followed circulatory failure. (3)Research indicates that poinsettias contain no chemicals commonly considered toxic; however, we do not recommend eating the plants. While most people are not sensitive to the sap, it can cause a mild skin irritation. [contradictory information] (4)It seems that it is not so a poisonous plant for human beings which may lead to consider it mo

(1)http://www.library.uiuc.edu/vex/toxic/crown/crown2.htm (2)Turner, R. Euphorbias. A Gardners Guide. (3)http://ianrpubs.unl.edu/horticulture/g1069.htm (4)http://www.botanical-online.com/alcaloidespoinsettiaangles.htm

4.08

moist habitats

4.09

(1)prefers partial shade or partial sun to full sun (2)Full sun but will tolerate some shade. (3)Poinsettias require four hours of direct sunlight a day.

(1)http://www.hortpix.com/pc1780.htm (2)http://www.floridata.com/ref/E/euph_pul.cfm (3)http://www.nybg.org/plants/plants/poins.html

4.1

(1)"well-drained soil" [because susceptable to many root-rot disease?] (2)rich, well-drained soil

(1)Dehgan, B. (1998) Landscape Plants for Subtropical Climates. University Press of Florida., Gainesville, FL. 638pp. (2)http://www.plantoftheweek.org/week059.shtml

4.11

Probably not - not a vine.

http://www.floridata.com/ref/E/euph_pul.cfm

4.12

No evidence

5.01

The species is a tall, rangy shrub that grows to a height of 10 feet.

http://www.floridata.com/ref/E/euph_pul.cfm

5.02

Euphorbiaceae

5.03

Euphorbiaceae

5.04

Euphorbiaceae

6.01

Has a luxuriant growth and flowers outdoors in tropical places and usually grown in hothouses in temperate places.

Turner. R. 1995. Euphorbias. A Gardners Guide.

6.02

AB: Poinsettia seeds without seed coats, cultured on a modified White's medium, germinated well (90%) and grew into normal seedlings.

Nataraja, K.; Chennaveeraiah, M. S.; Girigowda, P. (1973) In vitro production of shoot buds in Euphorbia pulcherrima. Current Science, 1973, Vol.42, No.16, pp.577-578, 3 ref.

6.03

Intensively bred but no records of inter-specific hybridization

6.04

'Each cyathium is actually a flower cluster or inflorescence containing unisexual, apetalous male and female flowers.' [don't know about self-fertilization]

http://waynesword.palomar.edu/trmar98.htm

6.05

'In poinsettia the ovary is hidden within the cyathium, but in other species the ovary protrudes out of the cyathium at maturity. The rim of the cyathium also bears one-several, greenish nectar glands that are attractive to insect pollinators.'

http://waynesword.palomar.edu/trmar98.htm

6.06

No evidence

6.07

Don’t know -- people grow it from cuttings, not seeds!

7.01

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

7.02

(1)Euphorbia pulcherrima, the poinsettia, is known all over the world as the flower of Christmas. (2)A pot or ornamental plant (Euphorbiaceae), produced seasonally (at Christmas), with red or white leaves, in some countries.  

(1)http://www.plantoftheweek.org/week059.shtml (2)http://www.agrobiologicals.com/glossary/G1733.htm

7.03

No evidence

7.04

Fruit a dry capsule, dehiscent [Euphorbia]

Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press

7.05

Probably not - No evidence that the species inhabits coastal, riverine or stream habitats.

7.06

Fruit a dry capsule, dehiscent [Euphorbia]

Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press

7.07

Fruit a dry capsule, dehiscent [Euphorbia]

Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press

7.08

No evidence of ingestion

8.01

not likely with limited flower number and 3 seeds/fruit [Euphorbia]

Wagner et al. 1990. Manual of the flowering plants of Hawaii. University of Hawaii Press

8.02

AB: Poinsettia seeds without seed coats, cultured on a modified White's medium, germinated well (90%) and grew into normal seedlings. [seems low viability when germinate in situ]

Nataraja, K.; Chennaveeraiah, M. S.; Girigowda, P. (1973) In vitro production of shoot buds in Euphorbia pulcherrima. Current Science, 1973, Vol.42, No.16, pp.577-578, 3 ref.

8.03

Stunted and abnormal leaves and bracts were observed in 3 commercial pot poinsettia crops, the injury being ascribed to volatilization of Treflan (trifluralin) used for glasshouse weed control. There were differences between crops in the degree and site of injury visible. At 2 nurseries the majority of the plants were unsaleable, the herbicide having been applied in mid-October when glasshouse ventilation was infrequent. At the third nursery, treated in June 2 months before the potted plants were moved into the house, activated carbon was applied to the soil as soon as herbicide damage was suspected. [quite sensitive to chemical herbicides]

Seeley, J. G. , Bing, A. 1976. Poinsettias injured by herbicide.New York State Flower Industries Bulletin, , No. 76, pp. 1, 5, 7

8.04

Keep the plant short and compact by pinching out the tips of new shoots until the middle of August.

http://www.plantoftheweek.org/week059.shtml

8.05

Don’t know