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Casuarina glauca Sieber

Swamp sheoak

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Description
  5. Germplasm
  6. Distribution
  7. Ecology
  8. Cultivation
  9. Harvesting
  10. Yields and Economics
  11. Energy
  12. Biotic Factors
  13. References


Has been recommended as a good candidate for restoring Haiti's eroded mountainsides and providing charcoal, fuelwood, and poles so desparately needed there. Grown as an ornamental, windbreak, and for cattle shade in southern Florida (but some Florida counties have laws banning its planting). In South Africa it is used for firewood, poles, reclamation, shelterbelts, timber, and windbreaks. Egyptians use the trees in rows for shelterbelts. To check spread by root suckers, they dig a ditch between the crop and the shelterbelt, allowing their goats and sheep to eat the exposed shoots before they become pests. The brownish timber is nicely marked and is used for fencing rails, shingles, and salt water pilings.

Folk Medicine

No data available.


Modulated seedlings of C. glauca increased their shoot N-content (proportional to protein content) by a factor of about 13 following the appearance of the nodules. Pollen may be allergenic.


Erect tree 10–15 (-30) m tall, the main stem moderately straight, often buttressed and fluted, the bark often cracked and flaky, the crown relatively sparse and narrow. Slender deciduous branchlets (ca 1 mm diameter) have 9–20 leaf teeth in remote whorls, short and broad, always tightly appressed. Male spikes dense, 1–2 1/2 cm long. Cones more or less cylindrical, ca 1–2 cm in diameter, much broader than long; valves 3–5 mm wide, in only 2 or 3 wheel-like rows. Seeds ca 700,000–970,000/kg.


Reported from the Australian Center of Diversity, swamp sheoak, or cvs thereof, is reported to tolerate high pH, limestone, low pH, salt and sanddunes, waterlogging, weeds, and wind. According to NAS, (1983e), this is a pest, in Florida. In Hawaiian pastures, where it spreads by root suckers, it is less cold-hardy than C. cunninghamiana. Still, it is said to be hardy to drought and frost in South Africa (NAS, 1983e). In fine-textured clays, even in waterlogged soils, C. glauca can develop a deep root system, while C. cunninghamiana and C. equisetifolia develop shallow roots and grow poorly. (2n = 18)


Found in a narrow belt hugging the coast of eastern Australia from Bega in New South Wales to Rockhampton in Queensland. It has also been successful in the marshes and saline soils of Israel, Cyprus, India, Kenya, Malawi, South Africa, Florida, and Egypt. Most common at edges of swampy flats near estuaries and tidal rivers; sometimes found on or near beach fronts. The flats may be only marginally above tidal limits; the water table is usually close to the surface (often with 30 cm of the surface).


It grows naturally on estuarine plains that are flooded with brackish tidal water, and also thrives on dunes at the seaside, often in the path of ocean spray. Ranges from sea level to 900 m in Hawaii. Reported to tolerate annual precipitation of 5 to 40 dm, estimated annual temperature of 18 to 28°C, and pH of 5 to 8. Rarely tolerates temperatures lower than -3°C. It has grown in Israel under a soil crust of salt (50,000 ppm). Although most natural stands are on acidic soils, it has grown well on alkaline clay-loam soils with shallow water tables in hot, semiarid areas of Central Australia. Thailand seedlings have tolerated high Ca levels and as much as 30% limestone. In southern Florida it flourishes on oolitic limestone. In Hawaii it is frequently planted on much weathered parent basalt in eroded blowouts, sometimes in holes blasted by dynamite. It also does well in pure limestone sand (NAS, 1983e).


In Hawaii seed are broadcast in spring and covered lightly with less than one cm soil. A seedling density of ca 200–325/m2 is recommended, but final densities should of course be much thinner (Ag. Handbook 450).


In continental U.S., seed bearing age is 4–5 years and flowering peaks from April–June, fruiting from September–December. Good seed crops occur annually (Ag. Handbook 450). Timber can be harvested as needed. Litter and firewood is often gathered as the accumulation justifies.

Yields and Economics

In Israel this outperforms other Casuarinas, reaching 20 m in 12–14 years, even on saline water tables. Based on what I read about other species, I would expect about 4 MT of litter and at least 4 MT wood per hectare per year under moderate management.


Casuarina spp. have very dense wood, with specific gravity 0.8–1.2, calorific value of ca 5,000 kcal/kg, splits easily, and burns slowly with little smoke or ash. It also can be burned when green, an important advantage in fuel short areas. From their fourth year, trees shed ca 4 tons cones/year. These, too, make good pellet-sized fuel (NAS, 1983e). Although N-nodulation is most successful at pH 6 to 8, some natural stands are well nodulated in acid soils (pH ca 4). Some of the root-suckering Casuarinas are discouraged except where the wood is needed. But in fuelwood plantations, cut trees rapidly regenerate from root sprouts and do not have to be replanted.

Biotic Factors

Browne (1968) lists the fungus Fomes badius. This species is reported to be less susceptible to the wilt and dieback attributed to the bacterium Pseudomonas on Casuarina equisetifolia.


Complete list of references for Duke, Handbook of Energy Crops
Last update Tuesday, December 30, 1997