Ability to Respond Total:10 / 25Ability to Respond = ( Ease of Response + Tools in Place )
Confidence:Medium
Confidence Notes:
Impact
Spread
Notes
Score
Spread Rate
The rate of Calla Lily's spread appears to be moderately increasing, invading more wetland habitats. It reproduces by bird-dispersed seeds and rhizomes, which can be spread by moving soil or garden clippings.
3
Spread Amount
Found along the North and South California Coast Ranges and San Francisco Bay area. It invades and displaces native plants in areas close to human settlements, particularly in coastal prairies, wetlands, and seeps.
3
Damage
Notes
Score
Ecological
Invasive in wetlands where it can create monocultures outcompeting native and desirable species. The plant is also poisonous which makes it undesirable to vertebrates.
2
Agricultural
Calla lily may be toxic to vertebrates due to the presence of oxalate crystals. Although rare on farmland, it invades meadows, pastures, and riparian areas, posing a risk of ill effects or death if consumed by livestock.
1
Infrastructure
0
Cultural
0
Health
Oxalate crystals are toxic to humans, but unlikely to be ingested
1
Benefit
Notes
Score
Ecological
Nectar source for several insects and hummingbirds
1
Agricultural
Very popular ornamental plant.
3
Infrastructure
Calla lilies have large rhizome networks and grow in wet areas, so they likely provide some erosion control in infested areas.
1
Cultural
Calla lilies are an attractive landscaping plant that people enjoy. Areas like Calla Lily Valley near Monterey are popular with the public.
2
Health
0
Total
3
Ability to Respond
Ease of Response
Notes
Score
Detection
Flowers are very identifiable, but rhizomes and leaves alone may not be. Seed spread by birds, rhizomes spread through soil
3
Control
Taxon and propagules are readily accessible, can be killed with straightforward methods, but rhizomes may be difficult to remove and persist in the soil for an unknown amount of time. It’s unknown how long the seed bank lasts.
3
Tools in Place
Notes
Score
Entry
Available through numerous horticultural websites.
0
Control
Not listed on the CCR 4500 list
3
Outreach
Some outreach materials on the identification and control of the species are available.
