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Species
Casuarina
IUCN
NCBI
EOL Text
Casuarina species have been reported to be monoecious (13) and dioecious (6); C. glauca in Florida has not been observed to bear female flowers. Flowering occurs principally from April to June, with numerous minute narrow and terminal male flowers crowded in rings among grayish scales, and rounded and lateral female flowers occurring in light-brown clusters (9,13). Female flowers are wind pollinated. The multiple fruit, gray brown and 8 to 15 mm (0.3 to 0.6 in) in diameter, ripen from September through December. Seed bearing usually begins by age 5, and good seed crops occur annually (13).
Early growth is rapid, and height increments exceeding 1.5 m (5 ft) per year are common. Mature trees in stands of C. cunninghamiana and C. equisetifolia may reach 32 m (105 ft) in height and 41 cm (16 in) in d.b.h.; more commonly, heights of 25 m (82 ft) and diameters of 25 cm (10 in) are attained. Initial survival rates for planted trees are acceptable, averaging over 87 percent. One 35-year-old stand of C. glauca had a basal area of 90 m²/ha (392 ft²/acre) composed of trees averaging 19 m (62 ft) in height and 14 cm (5.5 in) in d.b.h.
Total aboveground dry biomass yields of young natural stands of C. equisetifolia have been as high as 16.6 t/ha (7.4 tons/acre) per year. Such stands, with densities up to 11,400 trees per hectare (4,600/acre), have trees ranging from 0.6 to 18 cm. (0.25 to 7 in) in d.b.h., with an average of 4.3 cm (1.7 in) at an estimated age of 7.5 years.
The geographic seed origins of casuarina in Florida are not known. Although trees characteristic of each species can be readily located, classification of individual trees is sometimes difficult because a high degree of hybridization is presumed. The three species are found together in much of south Florida and have compatible flowering times. A C. cunninghamiana x C. glauca hybrid has grown faster than any of the three species (1). Studies of individual tree collections of C. cunninghamiana and C. equisetifolia from four areas in south Florida do not indicate differences among trees, sources, or species for survival through 6 months (16).
Casuarinaceae -- Casuarina family
D. L. Rockwood, R. F. Fisher, L. F. Conde, and J. B. Huffman
Casuarina species, native to Australia and neighboring areas, have been introduced into many countries. In the United States, three species have been established, primarily in Hawaii, California, and Florida: C. equisetifolia L. ex J. R. & G. Forst., C. cunninghamiana Miq. and C. glauca Sieber ex K. Spreng. Other common names of Casuarina are Australian-pine, beefwood, and horsetail-tree.
Barcode of Life Data Systems (BOLD) Stats
Specimen Records:69
Specimens with Sequences:63
Specimens with Barcodes:59
Species:18
Species With Barcodes:17
Public Records:50
Public Species:16
Public BINs:0
Casuarina equisetifolia and C. cunninghamiana are naturalized to the southwestern and southeastern coastal areas of Florida as far north as Tampa and Titusville, with C. equisetifolia particularly prevalent on beaches; C. glauca is present throughout the same general area, frequently as very dense stands along roads and fence lines. Casuarina cunninghamiana exists as planted trees as far north as Gainesville. In Hawaii, C. equisetifolia is common along sandy coasts and lowlands (9).
No commercial use is made of casuarina in Florida, although its pulping properties are acceptable (5) and reputed to be better than those of eucalyptus (Eucalyptus spp.) (8). The species have been widely used for shelterbelts and in landscaping as hedges and ornamentals (1); C. glauca has been frequently planted for soil stabilization near drainage ditches and lakeshores.
The species are well suited for fuelwood because of their fast growth rates, coppicing potential, and desirable wood properties. Their wood densities of approximately 0.72 are among the highest for Florida trees, their green wood moisture content is relatively low at 60 to 88 percent on an ovendry basis, and their whole-tree energy values are considerably higher than those of other species (16). The ash content is slightly higher than that of most native American woods, averaging about 2 percent; the ash content of bark is twice this amount. The wood dries rapidly and burns well. Attempts to saw and season casuarina for use as lumber have not been satisfactory (10). Casuarina bark has been used in tanning and medicine, and the fruits have been used for novelties and decorations (13).
All three Casuarina species prefer coarse-textured soils of the Entisol, Inceptisol, and Spodosol orders. They show wide latitude in their soil demands and range from dry, sandy beach ridges to wet lake margins, but they withstand inundation for short periods only. In southeastern Florida, the species are particularly prevalent on alkaline, lime stone-derived soils. Casuarina equisetifolia is tolerant of very saline conditions but grows best in slightly acid sandy soils. All three species tolerate low soil fertility but are quite responsive to fertilization with phosphorus or nitrogen and phosphorus. They reach maximum development in slightly depressional topography where adequate moisture is nearly always available.