'Casuarina' is a
genus of
shrubs and
trees in the Family
Casuarinaceae, native to
Australia and islands of the
Pacific. Once it was the sole genus in the family, but has been split into three genera (see
Casuarinaceae), a proposal that is not universally accepted.

Fruit of ''C. equisetifolia''
Commonly known as the 'she-oak' (sometimes '''sheoak'''), 'beefwood', or 'Australian pine', casuarinas are common in tropical and subtropical areas. The tree has delicate, slender ultimate branches and leaves that are no more than scales, making the tree look more like a wispy
conifer. The plants do especially well in wind-swept locations, and are widely planted as wind-breaks, although usually not in agricultural situations.
Plants of some species (''C. cunninghamiana'', ''C. equisetifolia'', ''C. glauca'') of the genus were introduced to parts of the
USA in the early
1900s, but are now considered
invasive species in these areas.
''Casuarina'' species are a food source of the
larvae of
hepialid moths: Members of the genus ''
Aenetus'', including ''A. lewinii'' and ''A. splendens'', burrow horizontally into the trunk then vertically down. ''
Endoclita malabaricus'' also feeds on ''Casuarina''.
The
noctuid Turnip Moth is also recorded feeding on ''Casuarina''.
The gum exuded from some ''casuarinas'' is edible and was a food source for
Aboriginal people.
Species accounts
★ '''Casuarina equisetifolia''' L. is a common tropical seashore tree known as Common Ironwood, Beefwood, Bull-oak, or Whistling-pine and is often planted as a windbreak. The wood of this tree is used for shingles, fencing, and is said to make excellent, hot burning firewood.
:''C''. ''equisetifolia'' is widespread in the
Hawaiian Islands where it is an introduced species, growing both at the seashore in dry, salty, calcareous soils and up in the mountains in high rainfall areas on volcanic soils. The plants are strongly suspected of having
allelopathic properties, as evidenced by the near absence of understory once a mat of litter develops around the plants.
★ '''Casuarina oligodon''' L. is a native tree of
New Guinea that is planted in an ancient (more than 3,000 years)
silviculture by highland gardeners practicing an intensive traditional
permaculture. The wood of this tree is used for building-timber, furniture and tools and is said to make excellent firewood. The tree's root nodules are known to fix nitrogen, and it is traditionally prized for its ability to increase the soil's fertility. Its abundant leaf-fall is high in nitrogen and traditionally prized for mulch.
★ '''Casuarina cunninghamiana''' (River Sheoak) is an introduced species in several countries, including
Argentina,
China,
Egypt,
Israel,
Iraq,
Kenya,
Mexico,
South Africa and the southern
United States [1]; in the United States it is now considered an
invasive species [2]. The species has nearly quadrupled in southern Florida over the last decade, as can be noted by
IFAS's
SRFer Mapserver.
The images below were photographed in Israel.
External links
★
USDA Forest service description
★ ''
Casuarina information from the Australian Government Department of Agriculture, Fisheries and Forestry''
★
Research team from
IRD working on
Casuarinaceae
★
USFS, FEIS

Kailua Beach on O‘ahu with casuarina trees on the beach dune