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

Asparagus densiflorus; Sprenger's asparagus fern

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

y

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

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

y

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

y

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

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

y

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

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

y

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

y

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

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

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

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

y

8.05

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

y=-1, n=1

Total score:

15

Source

Notes

1.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.

p.73 "severeal cultivars are recognized"

1.02

http://aquat1.ifas.ufl.edu/aspden.pdf

Naturalized in Florida

1.03

no evidence

2.01

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online Database] National Germplasm Resources Laboratory, Beltsville, Maryland. Available: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?300048 (10 March 2003)

Distributional range: Native: Africa: South Africa - Cape Province, Natal, Orange Free State, Transvaal

2.02

2.03

H.G. Jamieson., Kirstenbosch National Botanical Garden. November 2002.
Asparagus densiflorus.
Available: http://www.plantzafrica.com/plantab/asparagdens.htm

Distribution
Asparagus densiflorus grows in the coastal areas in the southeastern Cape and KwaZulu-Natal in a wide range of habitats, from coastal dunes to open rocky places or woods. It can be grown in USDA zones 9-10 and is hardy to -7°C (20 oF).

2.04

http://aquat1.ifas.ufl.edu/aspden.pdf

Naturalized in Florida

2.05

Hawaiian Ecosystems at Risk Project (HEAR) . Website available at: <http://www.hear.org/pier/asden.htm>

Presence: Pacific islands: Commonwealth of the Northern Mariana Islands (Tinian), Cook Islands (Rarotonga (cult.)), French Polynesia (Raiatea, Bora Bora), Guam (cult.), Hawai‘i, Marshall Islands (Kwajalein (cult.), Majuro (cult.)), Samoa (Upolu (cult.)), Tonga (Tongatapu (cult.), Vava‘u (cult.), Lifuka (cult.)).
Pacific rim: Australia (Queensland and New South Wales), New Zealand.
Indian Ocean islands: Christmas Island

3.01

http://aquat1.ifas.ufl.edu/aspden.pdf

Naturalized in Florida

3.02

no evidence

3.03

no evidence

3.04

(1)http://aquat1.ifas.ufl.edu/aspden.pdf (2)http://www.fleppc.org/01list.htm

(1)Found in large colonies on several scrub sites in Palm Beach County, displacing native ground cover and understory shrubs (Austin et al. 1992), and in Dade County, found in 7 local parks (R. Hammer, Miami-Dade County Parks Department, 1997 personal communication). Has escaped as well into tropical hammocks in Palm Beach County, overtopping young native plants such as wild coffee, Psychotria nervosa (A. Zahorcak, Florida Department of Environmental Protection, 1998 personal communication). Naturalized in barrier-island habitats of Sarasota County (K. A. Langeland, University of Florida, personal observation). Also reported from natural areas in Citrus, Lake, and Lee counties (EPPC 1996). (2)FLEPPC 2001 Invasive Plant List

3.05

http://www.land-care.net/bridal.html

Asparagus asparagoides causes serious economic and ecological losses

4.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.

p.72 "with short spines below the axils on the main stem"

4.02

no evidence

4.03

no evidence

4.04

http://edis.ifas.ufl.edu/UW137

deer resistant

4.05

no evidence

4.06

Wacker, T. L., M. L. Smither, et al. (1990). "Methods used to screen for Fusarium resistance in asparagus plants regenerated from protoplasts." Acta Horticulturae(271): 331-336.

AB: Protoclones of asparagus (Asparagus officinalis) cv. Jersey Giant were screened for enhanced resistance to F. oxysporum f.sp. asparagi and F. moniliforme [Gibberella fujikuroi].

4.07

(1)Russell, A.B, J.W.Hardin, L. Grand, and A. Fraser (1997) Poisonous Plants of North Carolina.online homepage. North Carolina Cooperative Extension Service, North Carolina State University. Available: http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm (2)http://www.amagickgarden.com/pages/amgpages/amgSHP.html

(1)Poisonous Part: Berries, contact with plant sap.
Severity: Cause only low toxicity if eaten. Skin irritation minor, or lasting only for few minutes. (2)plant presents no probable toxic threat to humans

4.08

low-growing shrub/ground cover of dry areas, might be flammable

4.09

(1)Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.(2)http://www.desert-tropicals.com/Plants/Liliaceae/Asparagus_Myers.html (3)http://www.desert-tropicals.com/Plants/Liliaceae/Asparagus_Myers.html

(1)p.73 "Fertile, moist soils in shaded or partially shaded places are prefered." (2)full sun or light shade (3)Full sun to light shade

4.1

(1)H.G. Jamieson., Kirstenbosch National Botanical Garden. November 2002.
Asparagus densiflorus.
Available: http://www.plantzafrica.com/plantab/asparagdens.htm (2)http://aquat1.ifas.ufl.edu/aspden.pdf

(1)"Asparagus densiflorus grows in most soils " (2)Thrives in any well-drained soil,has low nutrient requirements.

4.11

Weeds in New Zealand. Available: http://www.envbop.govt.nz/green/weed18.htm

"Has the potential to be similar to climbing asparagus which has a capacity to smother forest understory to a height of 2.5 - 5 m; smothers ground cover and can prevent regeneration of canopy species. "

4.12

no evidence

5.01

terrestrial

5.02

Liliaceae

5.03

no evidence

5.04

Hawaiian Ecosystems at Risk Project (HEAR) . Website available at: <http://www.hear.org/pier/asden.htm>

"Plants from tuberous roots"

6.01

no evidence

6.02

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.

p.73 "Propagate by seeds or division"

6.03

McCollum, G. D. (1988). "Asparagus densiflorus cultivars Sprengeri and Myers cross- pollinations with A. officinalis and other species." Asparagus Research Newsletter 6(1): 1-10.

AB: "No hybrids were produced from the cross A. densiflorus x A. officinalis in either direction. No other species hybridized successfully with A. densiflorus."

6.04

Camadro, E. L.1994.Genetic basis of low seed production in garden and ornamental asparagus. Asparagus Research Newsletter, 11:16-18

can be self- and cross-fertilized

6.05

http://www.plantzafrica.com/plantab/asparagdens.htm

no evidence, flowers are small, most often white or pale pink and are very sweetly scented

6.06

http://www.plantzafrica.com/plantab/asparagdens.htm

reproduces naturally by seeds only

6.07

no evidence

7.01

Weeds in New Zealand. Available: http://www.envbop.govt.nz/green/weed18.htm

"May originate from garden rubbish "

7.02

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.

used as an ornamental

7.03

no evidence

7.04

no evidence

7.05

no evidence

7.06

(1)Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.(2)http://aquat1.ifas.ufl.edu/aspden.pdf

(1)p.73 "Fruit a small, red, one to three-seeded, globose berry 6-12mm in diameter." (2)Seeds spread by birds

7.07

no evidence

7.08

bird-dispered

8.01

Whistler, A.W. (2000) Tropical Oramentals: a Guide. Timber Press, Inc., Portland, Oregon. 542pp.

p.73 "Fruit a small, red, one to three-seeded, globose berry 6-12mm in diameter." [realtively large sized seed, few seeds per fruit]

8.02

Maciel, N., N. Mogollon, et al. (1999). "Germination and emergence of four cut foliage Asparagus species." Revista de la Facultad de Agronomia 16(2): 160-166.

AB: Emergence parameters for the most popular Asparagus species for cut foliage (Asparagus densiflorus cv. Sprengeri, A. setaceus cv. Nanus, A. virgatus and A. officinalis) were determined under saranhouse conditions in Venezuela. Germination was hypogeal and chryptocotylar in all species. Total emergence was 44, 83, 60 and 88%, in the respective species. Emergence initiation (TI) occurred after 21, 18, 21 and 7 days, respectively, while 50% emergence (T50) was reached after 28, 21, 35 and 11 days, respectively. The time elapsed between the occurrence of 10% and 90% emergence (T10-90) was 13, 6, 20 and 12 days, respectively.

8.03

(1) Hawaiian Ecosystems at Risk Project (HEAR) . Website available at: <http://www.hear.org/pier/asden.htm>
(2) Weeds in New Zealand. Available: http://www.envbop.govt.nz/green/weed18.htm

(1) "Asparagus densiflorus has recently been found to be rather widespread in Hawai‘i on the island of Kaua‘i. There it is spreading along roadsides and invading secondary forest and seems to have the ability to withstand herbicide treatments used to control vegetation along roads " [related to tubers??]
(2) Chemical Control: Spray with Roundup + Pulse. Rate - Handgun 1 litre Roundup + 200 mls Pulse/100 litres water. Knapsack 100 mls Roundup + 20 mls Pulse/10 litres water.
Recommended Approach
Spray with Roundup.

8.04

(1)H.G. Jamieson., Kirstenbosch National Botanical Garden. November 2002.
Asparagus densiflorus.
Available: http://www.plantzafrica.com/plantab/asparagdens.htm (2)http://www.desert-tropicals.com/Plants/Liliaceae/Asparagus_Myers.html

(1)"The plants have extensive root systems with fairly large tubers, which are used in nature to provide food during long periods of drought in summer. They can be readily propagated by separating the tubers in fairly large clumps" [can regenerate from roots] (2)Cutting back the plants in late summer is often useful to rejuvenate the plants

8.05

no evidence