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Hypericum
canariense Introductions...
H. canariense has made its way to North America and other parts of the world as a relatively rare horticultural
offering. It is currently displayed at both the Los Angeles County Arboretum and
the Missouri Botanical Gardens, and it continues to appear for sale on occasion.
It has escaped ornamental planting in a
variety of areas...
Santa
Barbara, CA
Orange
County, CA
San Diego, CA
San
Mateo County, CA
San
Francisco, CA
Kula
(Maui), HI
Western
Australia
Victoria
(Australia)
New Zealand (no info yet)
Beyond
Eradication
Efforts/Techniques
See the Contacts page for a
list of people involved in following and eradicating this species
at each site.
Return to the Hypericum
canariense Home Page
Santa
Barbara, CA
H. canariense was first reported in the wild in the Santa
Barbara, CA area (Munz 1968), where it appeared to be escaping
from gardens (Smith 1976). I have looked for it in the Santa
Barbara region, but I have not found it there. It is also not
known to anyone I've spoken to at the universities and botanical
gardens in the area.
Munz, P. (1968). Supplement to A
California Flora. Berkeley, University of California Press.
Smith, C. (1976). A flora of the Santa Barbara region,
California: an annotated catalogue of the native and naturalized
plants of the Santa Barbara County mainland and nearby Channel
Islands. Santa Barbara, Santa Barbara Museum of Natural History.
Orange
County, CA
H. canariense covers about an acre on the
historic Dana Point headlands and several acres in San Juan
Capistrano. It was vouchered at both localities in the
mid-1980's, though it has been noted anecdotally as being in San
Juan Capistrano since at least the early 1970's. It appears not
to be spreading in Dana Point but is spreading widely in San Juan
Capistrano.

A large H. canariense in Lake Murray Park. |
San
Diego, CA
Within the city of San Diego, approximately three patches
of H. canariense cover several ha of coastal
scrub at the Pt. Loma Naval base. This invasion is likely
to have begun within the last twenty years (Calflora
database). I have also
seen several additional patches of H. canariense
in the San Diego area, residing in areas of coastal scrub
habitat of Tecolote Canyon, Balboa Park, and Lake Murray
Park. |
San
Mateo County, CA
In San Mateo Co., near Franklin Point on the central California
coast, H. canariense occurs in many dense patches, as
well as sporadic individuals, over about 100 ha of coastal scrub
and old fields. This invasion may have started as much as fifteen
years ago, but has increased rapidly during the last five years.

H.
canariense (yellow)in San Mateo Co.
(Photo by J. Wade - Summer 2001) |

Aerial photo of one portion
of the H. canariense (orange)
invasion in San Mateo. (Photo by J. Wade - Summer 2001) |
For more images of this invasion, see the
website www.hear.org/species/hypericum_canariense/johnwadeimages
San
Francisco, CA
A small population of this species (unconfirmed) is was treated with herbicides on Angel Island in San Francisco Bay in 2006.

Undergraduate technician Jodi Stewart climbing
H. canariense shrubs at Kula. (Summer 2003) |
Kula, Maui (Hawai'i)
H. canariense is also invading the Kula area
(rangeland, 1300m) on the island of Maui, HI. It has been
spreading away from an initial introduction near what is
now Kula Botanical Gardens for approx. 20 years
(pre-dating the gardens). The
HEAR (Hawaiian Ecosystems At Risk) website has additional
general and detailed
information about this invasion, including maps and
photos.
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Western
Australia
One coastal population has been identified here, about 300 km
south of Perth, in the Bremer Bay/Gairdner area (East of Albany).
Eradication has been planned (update required).
This population has been documented at the Western Australian
herbarium by specimens:
PERTH 05588499 (specimen from Bridgetown)
PERTH 05952999 (specimen from Bremer Bay)
Beyond
While these locations are few, this species has been successful
at spreading into natural, undisturbed vegetation, and appears
likely to increase its range substantially in the immediate
future. Its native range falls within the Mediterranean climate
zone, and similar habitat also occurs in Pacific North America,
Chile, New Zealand, Australia, and South Africa. The Nature
Conservancy has posted H. canariense on its Weed Alert list.
Eradication
Efforts
H. canariense will re-sprout if cut to the
ground, and there is no primary stem suitable for a weed wrench.
Thus far, eradication has been attempted via herbicide sprays. In
Hawai'i, control of H.canariense has been attempted using
the herbicide triclopyr ester (brand name Garlon 4). It is
susceptible to foliar treatment, but seasonally may not have
enough leaf surface available for uptake. It seems, at least in
Hawai'i, that it is quite susceptible to basal bark treatments at
any time of year (20% Garlon 4 in oil carrier).
(See the Contacts page for a
list of people involved in following and eradicating this species
at each site).
This page last updated: November
2008
This page is maintained by Katrina Dlugosch, University of
British Columbia.
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