Pacific Island Ecosystems at Risk (PIER)


Gaura lindheimeri


RISK ASSESSMENT RESULTS: Low risk, score: 6 (low risk based on second screen)


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

Gaura lindheimeri Engelm. & A. Gray. Family - Onagraceae. Common names - whirling butterflies, white gaura, butterfly gaura, large flowered beeblossom.

Answer

Score

1.01

Is the species highly domesticated? (If answer is 'no' then go to question 2.01)

n

0

1.02

Has the species become naturalized where grown?

1.03

Does the species have weedy races?

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”

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

2.04

Native or naturalized in regions with tropical or subtropical climates

n

0

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

1

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

3.04

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

y

2

3.05

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

y

1

4.01

Produces spines, thorns or burrs

n

0

4.02

Allelopathic

4.03

Parasitic

n

0

4.04

Unpalatable to grazing animals

y

1

4.05

Toxic to animals

n

0

4.06

Host for recognized pests and pathogens

n

0

4.07

Causes allergies or is otherwise toxic to humans

n

0

4.08

Creates a fire hazard in natural ecosystems

y

1

4.09

Is a shade tolerant plant at some stage of its life cycle

n

0

4.1

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y

1

4.11

Climbing or smothering growth habit

n

0

4.12

Forms dense thickets

5.01

Aquatic

n

0

5.02

Grass

n

0

5.03

Nitrogen fixing woody plant

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

n

0

6.01

Evidence of substantial reproductive failure in native habitat

n

0

6.02

Produces viable seed.

y

1

6.03

Hybridizes naturally

y

1

6.04

Self-compatible or apomictic

n

-1

6.05

Requires specialist pollinators

n

0

6.06

Reproduction by vegetative fragmentation

y

1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

1

1

7.01

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

n

-1

7.02

Propagules dispersed intentionally by people

y

1

7.03

Propagules likely to disperse as a produce contaminant

n

-1

7.04

Propagules adapted to wind dispersal

7.05

Propagules water dispersed

n

-1

7.06

Propagules bird dispersed

n

-1

7.07

Propagules dispersed by other animals (externally)

n

-1

7.08

Propagules survive passage through the gut

8.01

Prolific seed production (>1000/m2)

n

-1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

8.03

Well controlled by herbicides

y

-1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y

1

8.05

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

 

Total score:

6

Supporting data:

Notes

Reference

1.01

No evidence

1.02

1.03

(1) "G. lindheimeri was rarely seen in commercial production except for the white-flowering 'Whirling Butterflies,' which reaches 42 inches tall and 36 inches wide. That changed in 1994 when breeder Baldassare Mineo and his company Siskiyou Rare Plant Nursery in Medford, Ore., introduced 'Siskiyou Pink.' This cultivar was found as a pink-flowering sport of a white-flowering G. lindheimeri seedling. 'Siskiyou Pink' has a more spreading habit and tends to grow as wide as it is tall, 36 to 42 inches.
Several commercial cultivars have been produced from 'Siskiyou Pink,' including 'Sunny Butterflies,' 'Crimson Butterflies' and 'Blushing Butterflies.' These three cultivars were bred by Howard Bentley of Plant Growers Australia in Victoria, Australia."

(1) http://www.greenbeam.com/features/plant111300.stm

2.01

(1)Native:
NORTHERN AMERICA
Southeastern U.S.A.: United States - Louisiana [s.]
South-Central U.S.A.: United States - Texas (2)"White gaura is native to Louisiana, Texas and adjacent Mexico." [Temperate to Subtropical]

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.floridata.com/ref/G/gaur_lin.cfm

2.02

2.03

(1)Grows in Zones 5 - 9 (2)"Hardiness: USDA Zones 5 - 10." (3)Hardiness:
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)

(1)http://www.naturehills.com/new/product/perennialsdetails.aspx?
prodid=1404&ovchn=GGL&ovcpn=Perennials&ovcrn=gaura+lindheimeri&ovtac=PPC (2)http://www.floridata.com/ref/G/gaur_lin.cfm (3)http://davesgarden.com/guides/pf/go/37057/

2.04

(1)Native:
NORTHERN AMERICA
Southeastern U.S.A.: United States - Louisiana [s.]
South-Central U.S.A.: United States - Texas (2)"White gaura is native to Louisiana, Texas and adjacent Mexico." [Subtropical] (3) No specimens have been colllected in Mexico (4)Not native or naturalized in Florida [sub-tropic distribution is doubtful]

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.floridata.com/ref/G/gaur_lin.cfm (3)http://mobot.mobot.org/W3T/Search/vast.html (4)Wunderlin, R.P. Guide to the Vascular Plants of Florida.University Press of Florida.

2.05

(1)Cultivated and naturalized in Australia. (2)Introduced to Canada. (3)Introduced to U.K.

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.icangarden.com/neweden/blushingbutterflies.htm (3)http://www.gardeningexpress.co.uk/ProductDetails.asp?ProductID=10041

3.01

(1)cultivated & naturalized in Australia

(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl

3.02

No evidence

3.03

No evidence

3.04

(1)"Gaura lindheimeri was declared a noxious weed (Class 5) in NSW on the 1 March 2006. However, due to what can only be referred to as ‘communication breakdown’, the nursery industry was left with a lot of stock, so a furor erupted. After considerable government lobbying, the industry was granted a reprieve. Nurseries in NSW will be allowed to continue selling Gaura (and four other banned plants) until 30 November 2006. Gaura is also environmental weed in many areas of Australia, including Western Australia and South Australia. It’s not known to have naturalized in Victoria, but considering it self-seeds prolifically in many home gardens, this is surprising. ... In NSW, Gaura is a Class 5 noxious weed (on reprieve!). A Class 5 weed outbreak is termed ‘notifiable’, which means it must be reported. One of the control methods is to prevent the introduction of those plants into NSW, or the spread of those plants within NSW, or into another State."

(2)"Gaura lindheimerii has shown great tendencies to be invasive in California, eastern seaboard states and south Africa. It reseeds in Minnesota but the seedlings are not hardy."

(1)http://www.sgaonline.org.au/weed_gauralindheimeri.html (2)http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-Jan0104.html

3.05

Gaura coccinea, G. drummondii, and G. sinuata being controlled as weedy invasives. (1) Prevention and control: These Gaura species are native to the Great Plains of North America, extending from Mexico to Canada. Both Robbins (1951) and The Jepson Manual state that Gaura coccinea is native to California. However, these plants may become weedy in certain rangeland situations. There is little information available regarding the biology and ecology of these species. They are typically native grassland perennial herbs, which occupy dry sites, and do not appear to be negatively affected by grazing. The Jepson Manual describes Gaura drummondii and Gaura sinuata as "rhizomatous, forming dense mats," and Gaura coccinea as "woody stemmed and branched below ground." These characteristics allow these species to establish and persist in degraded range areas. Gaura coccinea has been observed to expand its native range northward into the southern interior grasslands of British Colombia. Continued expansion in California where heavy overgrazing occurs is very likely.
The key to management of these species is proper land use, before they become a problem. Avoid overgrazing dry range areas and reduce stocking rates in areas where these plants are patchy. If possible, minimize disturbance around patches to reduce the chances of spread.
Controlling established infestations is a very difficult task. Cultivation is not possible in many infested areas, and may spread rootstocks to new areas. Mowing may reduce seed production, but will not provide long-term control. Biocontrol for these plants is not a current option. Establishing competitive vegetation may prevent new seedlings from becoming established. However, these species are well adapted to grasslands and can persist in competitive healthy grassland environments.
There are certain herbicides that will provide short term control of these species. Glyphosate (2 quarts per acre) may be applied to actively growing infestations. Control may be better if applied in the fall, when then plants are actively translocating sugars to the roots. Control will be poor if plants are drought stressed or dusty. Glyphosate is a nonselective treatment and will injure or kill any other actively growing vegetation. Refer to the label for rates and precautions.

(1) http://www.cdfa.ca.gov/phpps/ipc/weedinfo/gaura.htm [3 Dec 2007]

4.01

No evidence (1) Description: White gaura is an herbaceous perennial that grows in a loose, bushy clump 2-4 ft (0.6-1.2 m) tall with a spread of 2-3 ft (0.6-0.9 m). The stems are slender and wiry, and covered with tiny hairs. The leaves are spoon shaped, 1-3 in (2.5-7.6 cm) long, with toothed margins. The flowers are produced above the foliage on erect spikes, 8-24 in (20.3-61 cm) long, that continue to elongate throughout the extended blooming period of late spring until first frost.

(1) http://www.floridata.com/ref/G/gaur_lin.cfm [3 Dec 2007]

4.02

Don't know

4.03

(1) No evidence

(1) http://scholar.google.com/scholar?q=%22Gaura%20lindheimeri%22+parasitic%7Cparasite [3 Dec 2007]

4.04

(1) Listed as very resistant to deer. (2) there are many plants which deer tend to avoid, year 'round or depending upon the season and what else is growing around them. Avoiding 'target' plants which deer clearly love is very important - once they come down to sample these, they often do damage to other neighboring plants as well. By the same token, planting many species which they find unpalatable will help to 'hide' other species which they have been known to enjoy. It is an ongoing challenge prone to regional differnces, but the plants listed here are generally known to be 'good risks'. [List includes G. lindheimeri]

http://www.orchardnurserynews.com/php/10deer_list_06.pdf

4.05

(1) Adverse factors: Common pests Poisonous parts Poisonous indications Internal poison: No; Dermatologic poison: No; Livestock poison: No

(1) http://www.crescentbloom.com/plants/specimen/GA/Gaura%20lindheimeri.htm [3 Dec 2007]

4.06

Probably not - (1)"No serious insect or disease problems. Root rot may occur in heavy, poorly drained soils." (2)Diseases/Insects - none serious (3)No pests or diseases are of major concern.

(1)http://www.mobot.org/gardeninghelp/plantfinder/Plant.asp?code=C840 (2)http://www.icangarden.com/neweden/crimsonbutterflies.htm (3)http://hort.ifas.ufl.edu/shrubs/GAULINA.PDF

4.07

(1) San Diego Regional Asthma Coalition: Low Allergy Plant and Tree List [List includes Gaura lindheimeri]

(1) http://www.asthmasandiego.org/pdfs/LowAllergyPlantList.pdf [3 Dec 2007]

4.08

Probably yes - (1)"This is a plant for hot climates and dry soils." (2)For Gaura species in general - "They tend to have woody stems and form dense mats or thickets, crowding or shading out other plant species. Some Gaura species are bushy, while others are low to the ground. Many bear delicate white flowers that turn red as they wither."

(1)http://www.floridata.com/ref/G/gaur_lin.cfm (2)http://en.wikipedia.org/wiki/Gaura

4.09

(1)Sun exposure - partial sun. (2)"Light: White gaura does best in full sun, but will tolerate partial shade." (3)Sun Exposure: Sun to Partial Shade

(1)http://www.naturehills.com/new/product/perennialsdetails.aspx?
prodid=1404&ovchn=GGL&ovcpn=Perennials&ovcrn=gaura+lindheimeri&ovtac=PPC (2)http://www.floridata.com/ref/G/gaur_lin.cfm (3)http://davesgarden.com/guides/pf/go/37057/

4.1

(1)Soil type - normal, sandy, clay (2)Soil pH requirements:
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)
(3)"It is adaptable to almost any soil and is tolerant of high humidity." (4)Soil tolerances - acidic; sand, loam and clay.

(1)http://www.naturehills.com/new/product/perennialsdetails.aspx?
prodid=1404&ovchn=GGL&ovcpn=Perennials&ovcrn=gaura+lindheimeri&ovtac=PPC (2)http://davesgarden.com/guides/pf/go/37057/ (3)http://www.icangarden.com/neweden/crimsonbutterflies.htm (4)http://hort.ifas.ufl.edu/shrubs/GAULINA.PDF

4.11

No evidence (1) Plant habit: round; spreading; Plant density: open

(1) http://hort.ifas.ufl.edu/shrubs/GAULINA.PDF [3 Dec 2007]

4.12

(1) "They tend to have woody stems and form dense mats or thickets, crowding or shading out other plant species. Some Gaura species are bushy, while others are low to the ground. Many bear delicate white flowers that turn red as they wither." [No further evidence].

(1) http://en.wikipedia.org/wiki/Gaura

5.01

(1) "White gaura is an herbaceous perennial that grows in a loose, bushy clump 2-4 ft (0.6-1.2 m) tall with a spread of 2-3 ft (0.6-0.9 m)."

(1) http://www.floridata.com/ref/G/gaur_lin.cfm

5.02

Onagraceae

5.03

Onagraceae

5.04

(1) Gaura has a deep carrot-like root that does not transplant well. Gaura’s long tap root allows it to survive drought situations.

(1) http://hort.ifas.ufl.edu/shrubs/GAULINA.PDF [3 Dec 2007]

6.01

No evidence

6.02

(1)"Propagation: White gaura is easy to grow from seed, and usually will self sow." (2)"G. lindheimeri seeds do not need to be pretreated and germinate in five to eleven days."

(1)http://www.floridata.com/ref/G/gaur_lin.cfm (2)Peters, William L.; Anderson, Neil O.

Statistical discrimination between pollen tube growth and seed set in establishing self incompatibility in Gaura lindheimeri Euphytica 149 (1-2) : 237-250 MAY 2006

6.03

(1)"Abstract: The University of Minnesota Gaura breeding program is developing USDA Z3-4 winter-hardy genotypes via interspecific hybridization of G. lindheimeri (Z5-6) and G. coccinea (Z2-4). Prior to commencing interspecific hybridization, the reproductive barriers operating in both parental species need to be characterized. The objective of this research was to determine the type and stability of reproductive barriers operating in G. lindheimeri by statistical comparisons between pollen tube growth and seed set in a full-sib diallel. Slowed or aborted pollen tube growth in the style indicated the presence of a gametophytic self incompatibility (SI) system. A statistical method, female (FCC) and male (MCC) coefficients of crossability, was used to verify that a stable SI system was operating and that other reproductive barriers were present. Several genotypes also expressed stage-specific inbreeding depression and incongruity. The simple linear regression equation for FCC/MCC, using pollen tube growth, was Y = 0.0124 + 0.974X, which was much closer to the expected Y = 0.0 + 1.0X (indicating a stable SI system) than the equation for seed set, Y = 0.012 + 0.910X. Using pollen tube length, both general combining ability (GCA) and specific combining ability (SCA) values were highly significant for G. lindheimeri (P <= 0.001). Histograms were used to delineate cut-offs to identify intra-incompatible/inter-compatible classes and S allele groups. Four possible classes were identified, but further research is needed to verify S allele genotypes." (2)"Of the 14 species of gaura in Texas, many are hard to identify as they readily hybridize." (3) Though natural hybrids of G. lindheimeri-G. longiflora have been reported, the degree of interspecific fertility in section Gaura is unknown...Natural hybrids with morning-opening flowers occur in mixed poplations of G, longiflora and G,lindheimeri, and G. demareei has been reported as far south as Nacogdoches and Harrison counties, Texas (Hoff and Nixon 1977).

(1)Peters, William L.; Anderson, Neil O. 2006. Statistical discrimination between pollen tube growth and seed set in establishing self incompatibility in Gaura lindheimeri Euphytica 149 (1-2) : 237-250. (2)http://www.seedsource.com/catalog/mixdetail.asp?PRODUCT_ID=1031 (3) B. L. Carr, D. P. Gregory, P. H. Raven and W. Tai. 1986. Experimental Hybridization and Chromosomal Diversity within Gaura sect. Gaura (Onagraceae). Systematic Botany 11(1): 98-111.

6.04

"G. lindheimeri, a diploid species (2n=2x=14) has been reported to be self-incompatible although the nature of the system has not been characterized."

(1) Peters, William L.; Anderson, Neil O. 2006. Statistical discrimination between pollen tube growth and seed set in establishing self incompatibility in Gaura lindheimeri Euphytica 149 (1-2) : 237-250.

6.05

Most species of Gaura appear to be pollinated by a broad set of insect pollinators. (1)"Gaura is of particular interest because of its diversity of pollination syndromes, including hawkmoth pollination, and …" (2)"Most gauras flower at sunset or sunrise. Fragrant flowers rich in nectar attract many pollinators including hummingbirds." (3) The primary species of Onagraceae studied had diverse insect visitors, and different insects served as primary pollen carriers for different species. Gaura villosa showed the greatest diversity, with at least 32 insect species carrying pollen, the major carriers being the antlion Scotoleon, 2 species of noctuid moths, and 2 halictid bees in Sphecodogastra. By contrast, the pollen carriers of G. coccinea were noctuid and geometrid moths; of Calylophus berlandieri one of the same species of Sphecodogastra, several chrysomelid and buprestid beetles (Coleoptera), and several beeflies (Diptera)

(1)Carr, Bruce L.; Crisci, Jorge V.; Hoch, Peter C. 1990. A cladistic analysis of the genus Gaura (Onagraceae) Systematic Botany 15 (3) : 454-461. (2)http://www.seedsource.com/catalog/mixdetail.asp?PRODUCT_ID=1031 (3) Clinebell, R, R., II., A. Crowe, D.P. Gregory, P.C. Hoch. 2004. Pollination ecology of Gaura and Calylophus (Onagraceae, Tribe Onagreae) in western Texas, U.S.A. Annals of the Missouri Botanical Garden 91 (3) : 369-400.

6.06

(1) "Several species, including G. coccinea, G. odorata, and G. glabra have invaded their way onto noxious weed lists in several states. Gaura lindheimeri shows no such tendencies to spread, either by rhizome or by seed." (2) It reproduces via seeds and also by rhizome growth.

(1) http://whatcom.wsu.edu/ag/homehort/plant/gaura.htm (2) Raven P. H., & Gregory, D. P. 1972. A revision of the genus Gaura (Onagraceae). Mem. Torrey Bot. Club 23: 1-96.

6.07

(1)"Suitable as annual" (2)"When grown from seed it will flower in the first year."

(1)http://www.mobot.org/gardeninghelp/plantfinder/Plant.asp?code=C840 (2)Peters, William L.; Anderson, Neil O. 2006. Statistical discrimination between pollen tube growth and seed set in establishing self incompatibility in Gaura lindheimeri Euphytica 149 (1-2) : 237-250.

7.01

No evidence of the species growing in heavy traffic areas.

7.02

(1)An ornamental plant - sold online.

(1)http://www.naturehills.com/new/product/perennialsdetails.aspx?
prodid=1404&ovchn=GGL&ovcpn=Perennials&ovcrn=gaura+lindheimeri&ovtac=PPC

7.03

Probably not - no evidence that the species grows in or around seed crops.

7.04

(1) Capsule woody, indehiscent, few-seeded. (2) Dispersal: Fine seed is probably mostly spread by wind, from plants in gardens (3)They are nut-like, indehiscent and 1/4 in. long. [contradicts ref #2 and is consistent with other references - seed are large with no evidence of wind dispersal]

(1) Raven, P.H. 1964. The Generic Subdivision of Onagraceae, Tribe Onagreae. Brittonia 16(3): 276-288. (2)http://www.southeastweeds.org.au/index.pl?page=106 (3)http://msuplants.com/pd.asp?pid=2129

7.05

(1) Capsule woody, indehiscent, few-seeded.

(1) Raven, P.H. 1964. The Generic Subdivision of Onagraceae, Tribe Onagreae. Brittonia 16(3): 276-288.

7.06

(1) Capsule woody, indehiscent, few-seeded.

(1) Raven, P.H. 1964. The Generic Subdivision of Onagraceae, Tribe Onagreae. Brittonia 16(3): 276-288.

7.07

No mechanisms for external attachment. (1) Capsule woody, indehiscent, few-seeded.

(1) Raven, P.H. 1964. The Generic Subdivision of Onagraceae, Tribe Onagreae. Brittonia 16(3): 276-288.

7.08

Don't know, probably not.

8.01

(1) One to four seeds develop in a four-angled woody capsule.

(1) http://www.killerplants.com/plant-of-the-week/20070716.asp

8.02

Don't know. (1) Capsule woody, indehiscent, few-seeded.

(1) Raven, P.H. 1964. The Generic Subdivision of Onagraceae, Tribe Onagreae. Brittonia 16(3): 276-288.

8.03

(1) There are certain herbicides that will provide short term control of these species. Glyphosate (2 quarts per acre) may be applied to actively growing infestations. Control may be better if applied in the fall, when then plants are actively translocating sugars to the roots. Control will be poor if plants are drought stressed or dusty. Glyphosate is a nonselective treatment and will injure or kill any other actively growing vegetation. Refer to the label for rates and precautions.

(1) http://www.cdfa.ca.gov/phpps/ipc/weedinfo/gaura.htm [3 Dec 2007]

8.04

(1)"If cut back in midsummer when flowering declines, gaura will regrow even bushier and bloom again in fall." (2)"A pruning in mid-summer will keep the Guara from getting leggy and floppy while encouraging more blooms." [extent of cutting not clear in these references] (3)may freeze back, the plant will resprout from the rootstock [recovers from severe trauma]

(1)http://www.floridata.com/ref/G/gaur_lin.cfm (2)http://davesgarden.com/guides/pf/go/37057/ (3)http://72.14.253.104/search?q=cache:jOZnbwWCKu8J:www.mswn.com/
Plant%2520Info%2520Sheets/Gaura%2520lindheimeri.pdf+
Gaura+lindheimeri+resprout&hl=en&ct=clnk&cd=1&gl=us

8.05

(1) There is no biological control method for plants of genus Gaura, and removing existing infestations is difficult, due in large part to the plants' ability to reproduce from bits of rhizome left in the ground.[Don''t know if enemies are present in Hawaii]

 

Need more info? Have questions? Comments? Information to contribute? Contact PIER!


[ Return to PIER homepage ] [Risk assessment page]


This page created 23 February 2008