California Invasive Plant Council

Myoporum laetum

Common names: ngaio tree; false sandalwood; mousehole tree

Myoporum laetum (ngaio tree) is an evergreen shrub or small tree (family Myoporaceae) found along the coast of California and in the San Francisco Bay region. It favors coastal areas, woodlands and riparian areas. This landscape ornamental has white flowers with purple dots and reddish-purple fruits. Ngaio tree has escaped cultivation in many areas, and is commonly found near urban areas. It is native to New Zealand. It may crowd out native plants, growing to form dense stands. It is susceptible to damage from the introduced myoporum thrips (Klambothrips myopori; Thysanoptera: Phlaeothripidae), which is believed to have slowed its spread.  A recently introduced thrips-resistant cultivar (Clean n Green) has also been evaluated as potentially invasive. Ngaio tree foliage contains toxic chemical compounds that can cause fatal liver damage in livestock, so grazing is not a control option. Mature plants are commonly treated by cutting at ground level and painting the stump with an herbicide.

Cal-IPC Rating: Moderate?

Explanation of Cal-IPC ratings

• High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
• Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
• Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
• Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
• Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

CDFA Rating: None?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
• -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Assessment(s)

Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

• Wildland Weed News. Cal-IPC. Vol 22, Issue 3
• Chinese pistache: Why isn’t it more invasive in California?. Rejmanek, Marcel. Vol 22, Issue 3
• Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2
• Roundup of Arundo projects reveals commitment, strategic weakness. Kelly, Mike. Vol 07, Issue 2
• Invasive New Zealand weeds: Our native plant invaders. Harris, Graham. Vol 06, Issue 4

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)

Other Myoporum laetum Information

• CalPhotos - Images of plants taken mostly in California.
• Calflora - Distribution map and records of this species in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• GBIF - Global distribution information.
• Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.
• The Plant List - Global taxonomic resource and collaborative clearinghouse from Kew Gardens, the Royal Botanic Gardens, the Missouri Botanic Garden and others.

Additional photos