Plant Assessment Form
More Hypericum canariense resources
Hypericum canariense
Synonyms: Hypericum floribundum
Common Names: Canary Island St. Johnswort; Grenadillo
Evaluated on: 13-Jan-05
List committee review date: 11/03/2005
Re-evaluation date:
Evaluator(s)
Univeristy of California - Santa Cruz
E E Biology/ EMS Santa Cruz, CA 95064
(831) 459-3677
dlugosch@biology.ucsc.edu
List committee members
Joe DiTomasoJohn Randall
Carla Bossard
General Comments
No general comments for this species
Table 2. Criteria, Section, and Overall Scores
Overall Score?
Moderate
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Alert Status?
Alert
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Documentation?
2 out of 5
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Score | Documentation | |||
1.1 | ?Impact on abiotic ecosystem processes | U. Unknown | Reviewed Scientific Publication | |
1.2 | ?Impact on plant community | A. Severe | Observational | |
1.3 | ?Impact on higher trophic levels | C. Minor | ||
1.4 | ?Impact on genetic integrity | U. Unknown | ||
2.1 | ?Role of anthropogenic and natural disturbance in establishment | B. Moderate | Other Published Material | |
2.2 | ?Local rate of spread with no management | B. Increases less rapidly | Anecdotal | |
2.3 | ?Recent trend in total area infested within state | B. Increasing less rapidly | Anecdotal | |
2.4 |
?Innate reproductive potential (see Worksheet A) |
A. High | Observational | |
2.5 | ?Potential for human-caused dispersal | C. Low | Anecdotal | |
2.6 | ? Potential for natural long-distance dispersal | C. Rare | Observational | |
2.7 | ?Other regions invaded | C. Already invaded | Other Published Material | |
3.1 |
?Ecological amplitude/Range (see Worksheet C) |
B. Moderate | Other Published Material | |
3.2 |
?Distribution/Peak frequency (see Worksheet C) |
D. Very low | Anecdotal |
Table 3. Documentation
Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".
Section 1: Impact | |
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Question 1.1 Impact on abiotic ecosystem processes? | U Reviewed Scientific Publication |
Identify ecosystem processes impacted: Sources of information: |
|
Question 1.2 Impact on plant community composition, structure, and interactions? |
A Observational |
Identify type of impact or alteration: Formation of monotypic stands, with no additional species below the canopy of this tall shrub. Sources of information: K. Dlugosch, Personal observation in California and Hawaii (2001-2005). |
|
Question 1.3 Impact on higher trophic levels? | C |
Identify type of impact or alteration: The entire family of Hypericum is poisonous to livestock. Seed is too small to be food for native species. Sources of information: Joe DiTomaso, UC Davis, pers. obs. |
|
Question 1.4 Impact on genetic integrity? | U |
Some native Hypericum but this species probably doesn't encounter them. Sources of information: Joe DiTomaso, UC Davis |
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Section 2: Invasiveness | |
Question 2.1 Role of anthropogenic and natural disturbance in establishment? |
B Anecdotal |
Describe role of disturbance: Soil disturbance or vegetation removal may provide sites of reduced competition and abundant light for new seedlings. Sources of information: Munz, P. (1968). Supplement to A California Flora. Berkeley, University of California Press. |
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Question 2.2 Local rate of spread with no management? | B Anecdotal |
Describe rate of spread: Local land owners/stewards have witnessed large increases in population size over (at least) the past five years. Sources of information: Warren McCord (Kula Botanical Gardens - Maui) - 2003 Personal communication |
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Question 2.3 Recent trend in total area infested within state? | B Anecdotal |
Describe trend: Rapid expansion at sites of intial introduction at several locations on the CA coast, but new foci of invasion have rarely been reported from other locations (though expansion through urban San Diego appears to be quite extensive). Sources of information: Mike Kelly (California Invasive Plant Council) - 2001 Personal communication |
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Question 2.4 Innate reproductive potential? | A Observational |
Describe key reproductive characteristics: Reproductive maturity is reached in as little as one year. Each fruit produces several hundred seeds, and large plants may produce a few hundred fruits. Seed production occurs every year from June through September. Viable fruits can be made via self-pollination or cross-pollination. Seed longevity is unknown. This plant will spread through underground rhizomes, but it is unclear how quickly this occrurs. Control has been attempted via topical herbicide, but plants resprout readily. Sources of information: Katrina Dlugosch - unpublished data |
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Question 2.5 Potential for human-caused dispersal? | C Anecdotal |
Identify dispersal mechanisms: Still sold as an ornamental but not widely cultivated. Sources of information: Consensus of weed committee. |
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Question 2.6 Potential for natural long-distance dispersal? | C Observational |
Identify dispersal mechanisms: Has very small seeds that fall to ground and probably are not spread far. Sources of information: Joe DiTomaso, UC Davis, pers. obs. |
|
Question 2.7 Other regions invaded? | C Other Published Material |
Identify other regions: Invading Mediterranean-type grasslands in Hawaii (Maui) and areas of Victoria and Western Australia, Australia. Sources of information: Maui: Wagner, W.L., D.R. Herbst, and S.H. Sohmer. 1999. Manual of the Flowering Plants of Hawai'i. 2 vols. Bishop Museum Special Publication 83, University of Hawai'i and Bishop Museum Press, Honolulu, HI. |
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Section 3: Distribution | |
Question 3.1 Ecological amplitude/Range? | B Other Published Material |
This species was introduced first as an ornamental at the turn of the 20th century, but was probably introduced to particular areas much later. All known invasions are in coastal areas receiving substantial inputs of fog. This habitat is similar to that of the native range, where H. canariense is common on the foggy sides of the mountainous Canary Islands, but is very rare on the drier faces. It is likely that H. canariense will continue to invade only the coastal areas of the state, but its success in both San Deigo and San Mateo counties suggests that it is a major threat to CA coast. Sources of information: Munz, P. (1968). Supplement to A California Flora. Berkeley, University of California Press. |
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Question 3.2 Distribution/Peak frequency? | D Anecdotal |
Describe distribution: Known invading populations: Sources of information: K. Dlugosch Personal Observations (2001-2005) |
Worksheet A - Innate reproductive potential
Reaches reproductive maturity in 2 years or less | Yes |
Dense infestations produce >1,000 viable seed per square meter | Yes |
Populations of this species produce seeds every year. | Yes |
Seed production sustained over 3 or more months within a population annually | Yes |
Seeds remain viable in soil for three or more years | Unknown |
Viable seed produced with both self-pollination and cross-pollination | Yes |
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes | Unknown |
Fragments easily and fragments can become established elsewhere | No |
Resprouts readily when cut, grazed, or burned | Yes |
Total points: | 7 |
Total unknowns: | 2 |
Total score: | A? |
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 Systems | marine systems | |
Freshwater and Estuarine | lakes, ponds, reservoirs | |
Aquatic Systems | rivers, streams, canals | |
estuaries | ||
Dunes | coastal | |
desert | ||
interior | ||
Scrub and Chaparral | coastal bluff scrub | |
coastal scrub | D, < 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 Communities | coastal prairie | D, < 5% |
valley and foothill grassland | ||
Great Basin grassland | ||
vernal pool | ||
meadow and seep | ||
alkali playa | ||
pebble plain | ||
Bog and Marsh | bog and fen | |
marsh and swamp | ||
Riparian and Bottomland habitat | riparian forest | |
riparian woodland | ||
riparian scrub (incl.desert washes) | ||
Woodland | cismontane woodland | |
piñon and juniper woodland | ||
Sonoran thorn woodland | ||
Forest | broadleaved upland forest | |
North Coast coniferous forest | ||
closed cone coniferous forest | ||
lower montane coniferous forest | ||
upper montane coniferous forest | ||
subalpine coniferous forest | ||
Alpine Habitats | alpine 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
- Central West
- Northwest
- Sierra Nevada
- Southwest