Amy Ferriter, South Florida Water Management District, Bugwood.org

Family: Casuarinaceae (Sheoak Family)

Synonym(s): Casuarina litorea

Duration: Perennial

Habit: Tree

Listed by:
Invasive Plant Atlas of the US: 1
Federal Noxious Weed: 0
TDA Noxious Weed: 0
TPWD Prohibited Exotic Species: 0

Description: Australian pine is a deciduous tree with a soft, wispy, pine-like appearance that can grow to 100 feet or more in height. Also known as ironwood, beefwood, she oak and horsetail tree, it bears a superficial resemblance to the conifer genus Pinus because of its small, round, cone-like fruits and its branchlets of scale-like leaves that look like pine needles. Its flowers are tiny, brown and wind-pollinated. The fruit is a nutlet about ? inch in diameter that contains winged seeds.

History: Australian pine was introduced to Florida in the late 1800's and planted widely for the purposes of ditch and canal stabilization, shade and lumber.

Biology & Spread: Australian pine is capable of flowering year- round and can produce tremendous numbers of small, winged seeds which are dispersed by wind.

Ecological Threat: Australian pine is fast-growing (5-10 feet per year), produces dense shade and a thick blanket of leaves and hard, pointed fruits, that completely covers the ground beneath it. Dense thickets of Australian pine displace native dune and beach vegetation, including mangroves and many other resident, beach-adapted species. Because its roots are capable of producing nitrogen through microbial associations, Australian pine can colonize nutrient-poor soils. Once established, it radically alters the light, temperature, and soil chemistry regimes of beach habitats, as it outcompetes and displaces native plant species and destroys habitat for native insects and other wildlife. Chemicals in the leaves of Australian pine may inhibit the growth of other plants underneath it.

The ground below Australian pine trees becomes ecologically sterile and lacking in food value for native wildlife. Unlike native shrubbery, the thick, shallow roots of Australian pine make it much more susceptible to blow-over during high wind events, leading to increased beach and dune erosion and interference with the nesting activities of sea turtles.

US Habitat: Australian pine occurs in open, coastal strand habitat, characterized by sand and shell beaches, rocky coasts, sand dunes, and sand bars in subtropical climates.

Distribution

US Nativity: Introduced to U.S.

Native Origin: Malaysia, southern Asia, Oceania and Australia

US States: FL, HI

Resembles/Alternatives: Locally native plants that are adapted to the harsh conditions of the coastal environment should be used for landscape planting and beach restoration projects. Because most of these shrub species are evergreen, they provide year-round shade, erosion control and essential food and shelter for native wildlife. A few examples of Atlantic and Caribbean natives include sea grape (Coccoloba uvifera), sea ox-eye daisy (Borrichia frutescens), sea hibiscus (Hibiscus tiliaceus), sea lavender (Tournefortia gnaphalodes) and sea-blight (Suaeda maritima).

Management: No biological controls are currently available for management of Australian pine. For new or small infestations, manual removal of Australian pine seedlings and saplings is recommended. For heavier infestations, application of a systemic type herbicide to bark, cut stumps, or foliage is likely to be the most effective management tool. Prescribed fire has also been used for large infestations in fire-tolerant communities.

Raking and removal of leaf litter, cones and seeds should be done whenever possible. Impacts to native plants should be minimized during any control activities. Whenever possible, efforts should be taken to prevent the introduction or encroachment of Australian pine. For example, recently disturbed beach habitat may be planted with native vegetation to prevent Australian pine from invading.

USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.

Listing Source

Texas Department ofAgriculture Noxious Plant List
Texas Parks and Wildlife Department Prohibited Exotic Species
Invaders Program
Federal Noxious Weed
Union of Concerned Scientists
United States Forest Service Southern Research Station

Text References

Florida Exotic Pest Plant Council. 1991. Exotic Woody Plant Control. In Florida Cooperative Extension Service, University of Florida, Ken Langeland, ed. pp 8-9.

Jubinsky, Greg A. and Andrew Leslie. 199?. "Casuarina." Bureau of Aquatic Plant Management, Technical Services Section, Tallahassee, Florida.

Nellis, David W. 1994. Seashore plants of South Florida and the Caribbean: a guide to identification and propagation of xeriscape plants. Pineapple Press, Inc., Sarasota, Florida.

Randall, J.M. and J. Marinelli. 1996. Invasive Plants: Weeds of the Global Garden. Brooklyn Botanic Garden Club Inc., Handbook No. 149. Brooklyn, New York. p. 30.

The Nature Conservancy. Australian Pine: Element Stewardship Abstract. In: Wildland Weeds Management & Research Program, Weeds on the Web.

Data Source

PCA APWG: Weeds Gone Wild (http://www.nps.gov/plants/ALIEN/fact/caeq1.htm)

Last Updated: 2007-11-08 by Jil M. Swearingen, National Park Service, Washington, DC