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Publication #ENH288

Casuarina spp.: Australian Pine1

Edward F. Gilman and Dennis G. Watson2

Introduction

Long-favored for use in erosion control along beaches, Australian pine tree is now outlawed in many parts of Florida due to its invasive nature, rapid growth rate, and non-native status. It is not a true pine tree and is not related to the pines. A straight, upright tree capable of reaching 70 to 90 feet in height and possessing rough, fissured, dark gray bark, Australian pine has what appear to be long, soft, gray/green needles but these "needles" are actually multi-jointed branchlets, the true leaves being rather inconspicuous. These "needles" sway gently in the breeze and give off a distinctive, soft whistle when winds are particularly strong. The insignificant flowers are followed by small, spiny cones, less than 1-inch-long.

Figure 1. 

Middle-aged Casuarina spp.: Australian pine


[Click thumbnail to enlarge.]

General Information

Scientific name: Casuarina spp.
Pronunciation: kass-yoo-ar-EYE-nuh species
Common name(s): Australian pine, casuarina
Family: Casuarinaceae
USDA hardiness zones: 9B through 11 (Fig. 2)
Origin: not native to North America
Invasive potential: According to the UF/IFAS Assessment of the Status of Non-Native Plants in Florida's Natural Areas (Fox et al. 2005), Casuaina spp. (Australian-pine) is prohibited for use in Florida.
Uses:
Availability: not native to North America

Figure 2. 

Range


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Description

Height: 70 to 90 feet
Spread: 30 to 40 feet
Crown uniformity: irregular
Crown shape: upright/erect
Crown density: open
Growth rate: fast
Texture: fine

Foliage

Leaf arrangement: whorled (Fig. 3)
Leaf type: simple
Leaf margin: entire
Leaf shape: scale-like
Leaf venation: unknown
Leaf type and persistence: evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy

Figure 3. 

Foliage


[Click thumbnail to enlarge.]

Flower

Flower color: yellow
Flower characteristics: not showy

Fruit

Fruit shape: round, oval
Fruit length: less than .5 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns
Pruning requirement: needed for strong structure
Breakage: susceptible to breakage
Current year twig color: green
Current year twig thickness: thin, medium
Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun, or partial shade
Soil tolerances: clay; sand; loam; alkaline; acidic; occasionally wet; well-drained
Drought tolerance: high
Aerosol salt tolerance: high

Other

Roots: can form large surface roots
Winter interest: no
Outstanding tree: no
Ozone sensitivity: unknown
Verticillium wilt susceptibility: unknown
Pest resistance: resistant to pests/diseases

Use and Management

Highly salt- and drought-tolerant, Australian pine was widely used in seaside landscapes as a windbreak, screen, clipped hedge, and for topiary. Its ability to withstand heat and other adverse conditions made Australian pine a favorite for street tree or specimen use also. It is not planted now due to the problems it has created including the elimination of habitat for native plants. Injured trees compartmentalize wounds poorly and decay advances rapidly through the trunk. Old trees which have been topped and abused often become hazardous and they can fall over or drop large limbs.

Growing in full sun or partial shade, Australian pine will tolerate many adverse conditions, dry or wet soil, heat or high winds. Trees are hardy to about 25°F. Vigorous sprouts often originate from the roots of older trees knocked back by the cold.

Pests

No pests are of major concern.

Diseases

Root rot.

Footnotes

1.

This document is ENH288, one of a series of the Environmental Horticulture, UF/IFAS Extension. Original publication date November 1993. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Edward F. Gilman, professor, Environmental Horticulture Department; Dennis G. Watson, former associate professor, Agricultural Engineering Department, UF/IFAS Extension, Gainesville, FL 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.