Plant Assessment Form

Genista monosperma

Synonyms: Retama monosperma; Spartium monosperma, Lygos monosperma

Common Names: bridal veil broom

Evaluated on: 12/20/04

List committee review date: 15/08/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org

List commitee members

Peter Warner
Jake Sigg
Joe DiTomaso
Cynthia Roye

General Comments

One population spread rapidly at Fallbrook Naval Weapons Station, San Diego County. A concern because this plant is sold in the horticultural trade.
Removed second scientific name, Retama monosperma, and added it to the synonym line 3/28/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? Alert
Documentation? 2 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Observational
Impact?
Four-part score BABD Total Score
B
1.2 ?Impact on plant community A. Severe Observational
1.3 ?Impact on higher trophic levels B. Moderate Observational
1.4 ?Impact on genetic integrity D. None Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Invasiveness?
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management A. Increases rapidly Observational
2.3 ?Recent trend in total area infested within state B. Increasing less rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
U. Unknown
2.5 ?Potential for human-caused dispersal B. Moderate Observational
2.6 ? Potential for natural long-distance dispersal B. Occasional Observational
2.7 ?Other regions invaded U. Unknown
3.1 ?Ecological amplitude/Range
(see Worksheet C)
C. Limited Observational
Distribution?
Total Score C
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very low Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? B Observational
Identify ecosystem processes impacted:

Fire risk and allelopathy unknown. Nitrogen fixer, so capable of altering soil nitrogen


Sources of information:

Jacobsen, E. 2000. pp. 266-268 in Bossard, C. M., J. M. Randall, and M. C. Hoshovsky (ed.) . 2000, Invasive plants of California's wildlands. University of California Press. Berkeley, CA


Question 1.2 Impact on plant community composition,
structure, and interactions?
A Observational
Identify type of impact or alteration:

Crowds out native vegetation, dominates grasslands and disturbed habitats.


Sources of information:

Jacobsen 2000


Question 1.3 Impact on higher trophic levels? B Observational
Identify type of impact or alteration:

habitat transformation Threatens habitat for endangered Stephen's kangaroo rat and threatened California gnatcatcher.


Sources of information:

Jacobsen 2000 - seems to be citing her own observations rather than published research


Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

none no native broom species


Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
A Observational
Describe role of disturbance:

Currently present in disturbed areas Occurs mostly in disturbed grassland near San Diego but is adapted to rocky slopes and sandy banks in Mediterranean climates, so has potential to spread. Spread by birds, so doesn't require disturbance.


Sources of information:

Jacobsen 2000


Question 2.2 Local rate of spread with no management? A Observational
Describe rate of spread:

spread from 10ac to 2000ac between 1994(?) and 1996 at the Naval Ordnance Center Annex in San Diego County


Sources of information:

Jacobsen 2000


Question 2.3 Recent trend in total area infested within state? B Observational
Describe trend:

Increases rapidly, but as of 2000 was still restricted to the Naval Ordnance Center


Sources of information:

Jacobsen 2000


Question 2.4 Innate reproductive potential? U
Describe key reproductive characteristics:

Each plant produces hundreds or thousands of seeds. Little known about physiology and reproductive mechanisms (1). Can propagate from cuttings (2). Based on other broom species, seeds probably remain viable for years and it can probably resprout after being cut, burned, or grazed.


Sources of information:

1. Jacobsen 2000
2. Curir, C., S. Sulis, P. Bianchini, A. Marchsini, L. Guglieri, and M. Dolci. 1992. Rooting herbaceous cuttings of Genista monosperma Lam.: seasonal fluctuations in phenols affecting rooting ability.


Question 2.5 Potential for human-caused dispersal? B Observational
Identify dispersal mechanisms:

May escape from plantings. Found in Cal-IPC nursery survey 2004


Sources of information:

Jacobsen 2000
Cal-IPC nursery survey (unpublished)
Brenzel, K. N. 2001. Sunset Western Garden Book. Sunset Publishing Company, Menlo Park, CA.


Question 2.6 Potential for natural long-distance dispersal? B Observational
Identify dispersal mechanisms:

Birds "appear" to be primary seed dispersers


Sources of information:

Jacobsen 2000


Question 2.7 Other regions invaded? U
Identify other regions:

Native to Spain and the Mediterranean.


Sources of information:

Section 3: Distribution
Question 3.1 Ecological amplitude/Range? C Observational

May have been cultivated in CA since 1917; escaped from a nursery (possibly) in 1990's. Only one population known as of 2000, in disturbed coastal scrub and grasslands in San Diego County.


Sources of information:

Jacobsen 2000


Question 3.2 Distribution/Peak frequency? D Observational
Describe distribution:

Only one population known as of 2000.


Sources of information:

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Unknown
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Unknown
Seed production sustained over 3 or more months within a population annually Unknown
Seeds remain viable in soil for three or more years Unknown
Viable seed produced with both self-pollination and cross-pollination Unknown
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Unknown
Fragments easily and fragments can become established elsewhere Yes
Resprouts readily when cut, grazed, or burned Unknown
Total points: 4
Total unknowns: 7
Total score: B?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrubD, < 5%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieD, < 5%
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): B
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions