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

Miscanthus floridulus (Miscanthus japonicus; Giant chinese silver grass, giant miscanthus, sword grass)

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

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

y

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

y

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

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

y

4.03

Parasitic

y=1, n=0

n

4.04

Unpalatable to grazing animals

y=1, n=-1

n

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

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

y

5.01

Aquatic

y=5, n=0

n

5.02

Grass

y=1, n=0

y

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

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

2

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

y

8.05

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

y=-1, n=1

Total score:

13

Source

Notes

1.01

No evidence

1.02

(1)It has become an invasive pest in Guam and other Pacific islands outside it native range (2)On the State of Hawaii noxious weed list.

(1)http://www.floridata.com/ref/M/misc_flo.cfm (2)http://www.hear.org/pier/miflo.htm

1.03

No evidence

2.01

(1)Giant miscanthus is native to Japan, the Ryukyu Islands, Taiwan, and other islands in that part of the Pacific. (2)Native to Japan and Pacific islands.

(1)http://www.floridata.com/ref/M/misc_flo.cfm (2)Hoticopia A-Z. CD-ROM database.

2.02

2.03

(1)Hardiness zones 6A to 11A (2)Growing at least to 1600 m in Taiwan

(1)Plant Master. CDROM database. Version 5.5 (2) Hsu FuHsing. 2000. Seed longevity of Miscanthus species. Journal of Taiwan Livestock Research, Vol.33, No.2, pp.145-153

2.04

(1)Giant miscanthus is native to Japan, the Ryukyu Islands, Taiwan, and other islands in that part of the Pacific. (2)Native to Japan and Pacific islands.

(1)http://www.floridata.com/ref/M/misc_flo.cfm (2)Hoticopia A-Z. CD-ROM database.

2.05

Introduced to the United States and several Pacific Islands.

(1)Hoticopia A-Z. CD-ROM database. (2)http://www.hear.org/pier/miflo.htm

3.01

(1)It has become an invasive pest in Guam and other Pacific islands outside it native range (2)On the State of Hawaii noxious weed list.

(1)http://www.floridata.com/ref/M/misc_flo.cfm (2)http://www.hear.org/pier/miflo.htm

3.02

See question 3.02

3.03

(1)on a list of agricultural weeds [japan] (2)On the State of Hawaii noxious weed list. (3)M. japonicus is listed as a serious weed in Indonesia.

(1)http://140.130.177.203/jgtsay/jg4-5-16.html#禾本科 (2) http://plants.usda.gov/plants (3)Holm et al. 1997. An electronic atlas of weeds and invasive plant. Version 1.0

3.04

(1)It has become an invasive pest in Guam and other Pacific islands outside it native range [no specific information on threats or impacts; mainly occurs on deforested, degraded agricultural land or steep eroded areas that resulted from deforestation; perhaps a disturbance weed, but no documented efforts of control could be found; it may be considered beneficial for slowin erosion on human-degraded, steep slopes]

(2)http://www.hear.org/pier/miflo.htm

3.05

Miscanthus sinensis is invasive in the SE USA, significant threat and/or severe threat

http://www.invasive.org/seweeds.cfm

4.01

(1) leaf margins contain silica and become sharp [cut through skin easily] (2)The leaves have saw-toothed edges that can cut the unwary gardener, it is best to wear gloves when working with the plant

(1)http://www.angrin.tlri.gov.tw/grasses/grasses66-67.htm (2)http://www.gardenbed.com/m/2375.cfm

4.02

(1) AB: "Leaf leachates and aqueous extracts of leaves and soil significantly inhibited lettuce growth."
(3) AB: Miscanthus floridulus and Digitaria decumbens were amongst the grassland spp. to show allelopathic effects.

(1)Chou, C H; Chung, Y T. 1974. The allelopathic potential of Miscanthus floridulus. Bot bull acad sin, new ser. 15 (1): 14-27.
(2)Chou, C H. 1975. Leaching of cations from Miscanthus floridulus and its asso ciated soils. Bot bull acad sin, new ser. 16 (1): 10-18.
[Above journals not available at UH]
(3) Chou, C. H. (1984) Allelopathy in tropical agroecosystems in Taiwan. Annual Report, Institute of Botany, Academia Sinica., 1984, pp.10-11

4.03

No evidence

4.04

(1) used as a fodder
(2) AB: "Normally, floret silvergrass is cut for hay at a height of about 1 m in Guizhou, China. The hay can be kept as a feed for cattle or sheep over winter."  

(1) Liang, J. C. (1980) Studies on leaf protein concentrate in Taiwan. II. Extractability and quality of leaf protein concentrate from different plants. Journal of the Taiwan Livestock Research, 1980, Vol.13, No.1, pp.53-74, 32 ref.
(2) Zhu BangChang (1989) On the cultivation and utilization of floret silvergrass (Miscanthus floridulus ) in the southern area of China. Proceedings of the XVI International Grassland Congress, 4-11 October 1989, Nice, France., 1989, pp.607-608, 6 ref.

4.05

No evidence

4.06

(1) This site lists 75 fungi species to be associated with M. floridulus. Puccinia erythropus also infests sugar cane [rust with relatively narrow range among grasses] (2) No serious pests or diseases

(1) http://nt.ars-grin.gov/fungaldatabases/all/FindRecOneFungusFrame.cfm(2)Hoticopia A-Z. CD-ROM database.

4.07

No evidence

4.08

old culms and leaves accumulate after seed set, likely to create a fire hazard

4.09

(1)Exposure: full sun. 'If planted in shady areas it will flop.' (2)prefers a semi shade to full sun position (3)sun or light shade

(1)Hoticopia A-Z. CD-ROM database. (2)http://plants.gardenbed.com/42/4186_lan.asp (3)http://www.cgf.net/cgi-bin/pages.pl?act=search&indexnumber=401

4.1

(1)Soil condition: Loamy to neutral (2) Sandy, loam; rich to well drained soils with neutral pH. (3)Prefers a deep fertile loamy soil that does not dry out in summer[200] but it also succeeds in any ordinary soil that is not too dry[; does not tolerate heavy clay soils.

(1)Hoticopia A-Z. CD-ROM database. (2)Plant Master. CDROM database. Version 5.5 (3)http://www.gardenbed.com/m/2375.cfm

4.11

Probably not - not a vine.

Hoticopia A-Z. CD-ROM database.

4.12

(1)Aggressive, forming dense communities. (2)The almost total lack of other species in M. floridulus stands throughout Taiwan was studied …

(1)http://www.hear.org/pier/miflo.htm (2)Chou, C. H.; Chung, Y. T.1974. The allelopathic potential of Miscanthus floridulus.Botanical Bulletin of Academia Sinica, , Vol.15, No.1, pp.14-27

5.01

5.02

A 10 to 15 feet tall perennial grass.

Hoticopia A-Z. CD-ROM database.

5.03

5.04

AB: "Rhizome reserve carbohydrate contents decreased from mid-Sep. until Mar. when they increased again; the level also decreased from late May and increased again in Aug. The number of regrowth shoots after cutting and yield decreased with increased cutting frequency. Regrowth ability was positively related to the rhizome reserve starch content. " [rhizome as reserve to reshooting, but no indication of whether storage is extensive enought to be considered a geophyte]]

Wang, Y. C.; Lee, M. L. (1991) The distribution of reserve carbohydrates and their relationship with shooting ability in Miscanthus species in Taiwan. Journal of Taiwan Livestock Research, 1991, Vol.24, No.1, pp.41-50, 18 ref.

6.01

fertile lemma with awn 8-10 mm long

http://www.hear.org/pier/miflo.htm

6.02

'Seeds of M. floridulus were collected and germinated in a petridish under low light and seedlings were planted in pots.'

Kao W, Tsai, T. and W. Chen. 1998. Annals of Botany. 81(2): 295

6.03

Intergeneric hybrids procured with Saccharum.[not natural]

http://biodiversity.uno.edu/delta/grass/www/m'anthus.htm

6.04

No information

6.05

grass species - wind

http://plants.gardenbed.com/42/4186_flo.asp

6.06

(1)Propagation: division; seeds. [division = artificial propagation] (2)Although it is technically a clump grass and not a turf-forming grass, giant miscanthus spreads and enlarges slowly with short underground rhizomes. [not adequate evidence for natural reproduction by fragmentation]

(1)Hoticopia A-Z. CD-ROM database. (2)http://www.floridata.com/ref/M/misc_flo.cfm

6.07

(1)Although of great stature and very striking may take a few years to really establish (3)Three years of growth should produce a good sized specimen [estimate that no flowers in first year if grown from seed, given huge size of mature plants and the statements above]

(1)http://www.lds.co.uk/fhf/miscanth.htm (2)http://www.planterspalette.com/articles/perennials/decorgrasses.htm

7.01

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

http://www.hear.org/pier/miflo.htm

7.02

(1) Attractive foliage. Suitable for cut flowers and dry flowers.
(2)AB: " The local people propagate the plants by division or cuttings."

(1) Hoticopia A-Z. CD-ROM database.
(2) Zhu BangChang (1989) On the cultivation and utilization of floret silvergrass (Miscanthus floridulus ) in the southern area of China. Proceedings of the XVI International Grassland Congress, 4-11 October 1989, Nice, France., 1989, pp.607-608, 6 ref.

7.03

Probably not - seeds relatively large - 'fertile lemma with awn 8-10 mm long.'

http://www.hear.org/pier/miflo.htm

7.04

No evidence - but probably yes as it is a grass species.

7.05

Probably not - no evidence that the species is riparian or coastal.

7.06

no evidence

7.07

no evidence

7.08

seeds might be indidentally consumed by grazers

8.01

No estimate available

8.02

AB: "The germination ability of the seeds stored in ambient conditions for 6 months was reduced drastically. No germination was observed after storing in ambient conditions for periods of 12 months or more."; "It was concluded that Miscanthus seeds might lose their germination ability 6 months after being dispersed by the wind under natural conditions."

Hsu FuHsing (2000) Seed longevity of Miscanthus species. Journal of Taiwan Livestock Research, 2000, Vol.33, No.2, pp.145-153, 11 ref.

8.03

No evidence

8.04

Burning does not kill the plants, as it quickly regenerates from the underground parts

http://www.hear.org/pier/miflo.htm

8.05

Don’t know