Plant Assessment Form

Crocosmia x crocosmiiflora

Synonyms: derived from C. pottsii X C. aurea; Tritonia X crocosmiiflora

Common Names: montbretia

Evaluated on: 8/25/04

List committee review date: 25/10/2017

Re-evaluation date:

Evaluator(s)

Peter Warner
California Department of Parks and Recreation, Mendocino District
P. O. Box 603, Little River, CA 95456-0603
707/937-9172; 707/937-2278
pwarner@mcn.org

List commitee members

Alison Stanton
Jake Sigg
Cynthia Roye
John Randall
Joe DiTomaso
Peter Warner

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U Reviewed Scientific Publication
Impact?
Four-part score UCCD Total Score
C
1.2 ?Impact on plant community C. Minor Other Published Material
1.3 ?Impact on higher trophic levels C. Minor Observational
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
15 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 Other Published Material
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Other Published Material
2.5 ?Potential for human-caused dispersal A. High Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare Other Published Material
2.7 ?Other regions invaded B. Invades 1 or 2 ecological types Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Other Published Material
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
C. Low Other Published Material

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? U Reviewed Scientific Publication
Identify ecosystem processes impacted:

None known. No literature on ecological impacts has been located.


Sources of information:

None


Question 1.2 Impact on plant community composition,
structure, and interactions?
C Other Published Material
Identify type of impact or alteration:

Sources of information:

Nursery and Garden Industry Austraila @ http://www.ngia.com.au/np/2000No12/00-12.html
Warner, PJ. 2004. Personal observations, San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties, 1999-2004. pwarner@mcn.org; 707/937-9172.


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

None known; flowers are likely attractive to hummingbirds and perhaps butterflies. Observed displacing native Rubus species, a native food source for wildlife. No information in scientific literature; personal observation and web posting of hummingbird activity


Sources of information:

Warner, PJ. 2004. Personal observations, San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties, 1999-2004. pwarner@mcn.org; 707/937-9172.
The Louisiana Museum of Natural History @ http://www.museum.lsu.edu/~Remsen/HUMNETf/Crocosmia.html


Question 1.4 Impact on genetic integrity? D Other Published Material

None known; unlikely since no congeners exist in native California flora. Inferred from general knowledge of genetics and evolution.


Sources of information:

Hickman, JC. 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, CA. p. 1152.
Warner, PJ. 2004. Inference based on plant genetics and horticultural concepts.


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

Crocosmia is a widely cultivated garden plant, so does well with soil disturbance; often found in areas disturbed by human activities; horticulturalists cite the need to thin stands about every 3 years for maximum garden performance (flowering); also observed off trails, especially in damp forests and woodlands. From web-posted horticultural requirements, somewhat dependent upon disturbance of soil. However, montbretia is also capable of spreading without human intervention (personal observation).


Sources of information:

The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com; www.weedinfo.com.au/wd_crcro.htm;
Nursery and Garden Industry Australia @ http://www.ngia.com.au/np/2000No12/00-12.html
Warner, PJ. 2004. Observations from 1986-2003 in residential landscapes and wildlands in Sonoma Co.; Golden Gate National Recreation Area; Pt. Reyes National Seashore; Mendocino County. 707/937-9172; pwarner@mcn.org.


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

Observed to spread slowly at first, then more rapidly, within a single patch. Can also spread to adjacent areas through seed or cormlet dispersal. My observations suggest that once a new plant is established, it will expand rapidly to occupy more space. Once flowering is initiated, seeds can spread plants to nearby unoccupied sites (within several meters).


Sources of information:

The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com; www.weedinfo.com.au/wd_crcro.htm;
Ingwersen Nursery @ http://www.ingwersen.co.uk/Crocosmia%20x%20crocosmiiflora.htm
Warner, PJ. 2004. Observations from 1986-2004 in residential landscapes and wildlands in Sonoma Co.; Golden Gate National Recreation Area; Pt. Reyes National Seashore; Mendocino County. 707/937-9172; pwarner@mcn.org..


Question 2.3 Recent trend in total area infested within state? B Other Published Material
Describe trend:

Estimated to be slowly increasing as new plantings and dispersal mechanisms lead to new introductions and establishment. Not known as invasive in interior California _ reports found are all coastal, so some habitats may still be yet to be exploited


Sources of information:

Redwood National Park @ www.nps.gov/redw/exot2000.doc
Nursery and Garden Industry Australia @ http://www.ngia.com.au/np/2000No12/00-12.html;
California Invasive Plant Counil @ ucce.ucdavis.edu/freeform/ceppc/documents/ 2002_Symposium_Proceedings1997.pdf


Question 2.4 Innate reproductive potential? B Other Published Material
Describe key reproductive characteristics:

Corms (bud from existing corms); seeds Corms and seeds are both viable reproductive mechanisms.


Sources of information:

Hickman, JC. 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, CA. p. 1152.
The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com; www.weedinfo.com.au/wd_crcro.htm;
Ingwersen Gardens @ http://www.ingwersen.co.uk/Crocosmia%20x%20crocosmiiflora.htm


Question 2.5 Potential for human-caused dispersal? A Other Published Material
Identify dispersal mechanisms:

Sold commercially; entire plants, corms, seeds spread as garden waste debris; spreads from horticultural plantings to adjacent areas from corms that bud prolifically; also produces seed that is easily dispersed by water, in soil movement (perhaps by animals or on human footwear) Numerous mechanisms for dispersal, and most based on human activities.


Sources of information:

The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com;
Weed Information @ www.weedinfo.com.au/wd_crcro.htm;
Warner, PJ. 2004. Personal inference.


Question 2.6 Potential for natural long-distance dispersal? C Other Published Material
Identify dispersal mechanisms:

Corms and seeds can float; wind dispersal very unlikely; dispersal by animals unknown (seed ingestion by birds?); seeds are viable in warm moist areas Long-distance dispersal mechanisms appear lacking, although the potential for long-distance seed dispersal is unknown.


Sources of information:

The Plants Database @ http://plantsdatabase.com;
The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com
Warner, PJ. 2004. Personal inference.


Question 2.7 Other regions invaded? B Other Published Material
Identify other regions:

Sources of information:

The Plants Database @ http://plantsdatabase.com;
The Garden of Paghat the Ratgirl @ www.paghat.com/crocosmia2.html;
Floridata @ www.floridata.com;
Dept. of Agriculture, Western Australia @ http://agspsrv34.agric.wa.gov.au/progserv/plants/weeds/weedsci4.htm;
Dept. of Conservation (New Zealand) @ http://www.doc.govt.nz/Conservation/003~Weeds/south-island-wilding-conifer-strategy/Appendix-One.asp


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Other Published Material

Occurs in coastal ecological types only in CA; well-established in CA gardens Reports and observations


Sources of information:

Redwood National Park @ www.nps.gov/redw/exot2000.doc;
Calif. Invasive Plant Council @ ucce.ucdavis.edu/freeform/ceppc/documents/ 2002_Symposium_Proceedings1997.pdf;
Warner, PJ. 2004. Observations from 1986-2004 in residential landscapes and wildlands, Sonoma Co.; Golden Gate National Recreation Area; Pt. Reyes National Seashore; Mendocino County. 707/937-9172; pwarner@mcn.org.


Question 3.2 Distribution/Peak frequency? C Other Published Material
Describe distribution:

Sporadic, may be more extensive than perceived due to vegetative similarity to Iris species Reports and observations


Sources of information:

Redwood National Park @ www.nps.gov/redw/exot2000.doc;
California Invasive Plant Council @ ucce.ucdavis.edu/freeform/ceppc/documents/ 2002_Symposium_Proceedings1997.pdf;
Warner, PJ. 2004. Observations from 1986-2004 in residential landscapes and wildlands, Sonoma Co.; Golden Gate National Recreation Area; Pt. Reyes National Seashore; Mendocino County. 707/937-9172; pwarner@mcn.org.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter No
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
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 Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 4
Total unknowns: 2
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
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
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 woodlandD, < 5%
Forestbroadleaved upland forestC, 5% - 20%
North Coast coniferous forestD, < 5%
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): C

Infested Jepson Regions

Click here for a map of Jepson regions

  • Central West
  • Northwest
  • Southwest