dcsimg

Common Names

provided by Fire Effects Information System Plants
More info for the term: tree

For Cunningham casuarina:
river sheoak
river-oak
sheoak
she-oak

For Casuarina equisetifolia:
beach sheoak
Australian-pine
horestail casuarina

For Casuarina glauca:
grey sheoak
ironwood
longleaf casuarina
whistling pine


TAXONOMY:
The scientific name of the sheoak genus is Casuarina (Casuarinaceae) [12,19].
Three species of sheoak are common in the United States. All will be treated
in this report because of their similar status as invader species and
across-the-board efforts to eradicate the genus from the continent.
"Sheoak" refers to the genus. The species covered in this review are:

Casuarina cunninghamiana Miq., river sheoak
Casuarina equisetifolia L., beach sheoak
Casuarina glauca Seiber, gray sheoak [6,19]

These species hybridize with each other [14].


LIFE FORM:
Tree


FEDERAL LEGAL STATUS:
NO_ENTRY


OTHER STATUS:
All 3 species of sheoak are list as noxious weeds (prohibited aquatic
plants, Class 1) in Florida [16].





DISTRIBUTION AND OCCURRENCE
SPECIES: Casuarina spp.
GENERAL DISTRIBUTION:
Sheoaks were introduced to the United States near the turn of the
20th century [14]. They are widely distributed in southern Florida
and are also found in California, Arizona, and Hawaii [12,17].




Distributions of river, beach, and gray sheoak. Maps courtesy of USDA, NRCS. 2018. The PLANTS Database.
National Plant Data Team, Greensboro, NC [2018, June 8] [16].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Conservation Status

provided by Fire Effects Information System Plants
All 3 species of sheoak are list as noxious weeds (prohibited aquatic
plants, Class 1) in Florida [16].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Distribution

provided by Fire Effects Information System Plants
Sheoaks were introduced to the United States near the turn of the
20th century [14]. They are widely distributed in southern Florida
and are also found in California, Arizona, and Hawaii [12,17].


Distributions of river, beach, and gray sheoak. Maps courtesy of USDA, NRCS. 2018. The PLANTS Database.
National Plant Data Team, Greensboro, NC [2018, June 8] [16].






license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Fire Management Considerations

provided by Fire Effects Information System Plants
More info for the term: peat

Periodic fires coupled with the use of herbicides may be an effective
method of controlling sheoak. However, too frequent, intense
fires that kill overstory native pines may actually encourage Casuarina
species to establish [18]. Morton [14] warns that burning Australian
pine in peat soils may be hazardous. Elfer [3] suggests that fire may
be an effective control method for trees greater than 3 inches (8 cm) in
diameter and in dense stands. Burning could be potentially harmful if
the soil pH is changed such that native species cannot establish [3].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Key Plant Community Associations

provided by Fire Effects Information System Plants
River sheoak is listed as a component in the following vegetation
types:

Area Classification Authority
Mariana Is, S. Pacific veg. type Falanruw & others 1989 [5]


Palau, S. Pacific veg. type Cole & others 1987 [2]
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Life Form

provided by Fire Effects Information System Plants
More info for the term: tree

Tree
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Management considerations

provided by Fire Effects Information System Plants
Sheoak is extremely fast growing, crowding out many native
plants and creating sterile environments for both plants and animals
[10]. It forms dense roots, which deplete soil moisture and break water
and sewer lines. It is also susceptible to windthrow during hurricanes
[3]. Cutting often induces sprouting, so it is not an effective control
method. Chemicals, such as 2,4,5-T, 2,4-D, or Garlon 3A, can be used to
eradicate sheoak [10,14].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Phenology

provided by Fire Effects Information System Plants
More info on this topic.

More info for the terms: fruit, seed

Sheoak can flower and fruit year-round in warm climates [3].
Its peak flowering time is between April and June, and its peak fruiting
time is between September and December. The minimum seed-bearing age is
4 to 5 years, and it produces a good seed crop annually. C.
equisetifolia usually flowers and fruits two times a year: between
February and April, and September and October. It produces fruit in
June and December. The fastest growth occurs in the first 7 years with
maximum growth reached in 20 years. The maximum lifespan of Australian
pine is 40 to 50 years [3].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Post-fire Regeneration

provided by Fire Effects Information System Plants
More info for the terms: caudex, root crown, secondary colonizer, seed

survivor species; on-site surviving root crown or caudex
off-site colonizer;seed carried by wind; postfire years 1 and 2
off-site colonizer; seed carried by animals or water; postfire yr 1&2
secondary colonizer; off-site seed carried to site after year 2
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Taxonomy

provided by Fire Effects Information System Plants
The scientific name of the sheoak genus is Casuarina (Casuarinaceae) [12,19].
Three species of sheoak are common in the United States. All will be treated
in this report because of their similar status as invader species and
across-the-board efforts to eradicate the genus from the continent.
"Sheoak" refers to the genus. The species covered in this review are:

Casuarina cunninghamiana Miq., river sheoak
Casuarina equisetifolia L., beach sheoak
Casuarina glauca Seiber, gray sheoak [6,19]

These species hybridize with each other [14].
license
cc-publicdomain
bibliographic citation
Snyder, S. A. 1992. Casuarina spp. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Associated Forest Cover

provided by Silvics of North America
When casuarina is present through natural seeding in Florida, it tends to form pure stands that are often nearly devoid of other vegetation (4). It may coexist with vegetation such as Florida fishpoisontree (Piscidia piscipula), button-mangrove (Conocarpus erectus), myrsine (Rapanea punctata), stopper (Eugenia spp.), randia (Randia spp.), cocoplum (Chrysobalanus icaco), southern bayberry (Myrica cerifera), redbay (Persea borbonia), and Florida poisontree (Metopium toxiferum) (3).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Climate

provided by Silvics of North America
In Australia, these species grow in the tropical and subtropical north and east: C. cunninghamiana along rivers, C. glauca in swamps, and C. equisetifolia along the coast.

In Florida, C. cunninghamiana and C. glauca have a wide tolerance for moisture regimes, as they are present on sites ranging from dry to very wet but not permanently flooded. Casuarina equisetifolia performs well on dry sites only; C. glauca appears to be the most frost hardy, although it will not withstand long periods below freezing, and C. cunninghamiana is intermediate in frost tolerance. There seem to be no climatic barriers to sexual reproduction.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Damaging Agents

provided by Silvics of North America
Casuarina appears to have relatively few insect problems. The twig girdler (Oncideres cingulata) is harmful only to small trees; damage by the leaf notcher weevil (Artipus floridanus) usually is inconsequential; and one species of spittlebug (Clastoptera undulata) appears to infest individual trees but causes no serious damage (2). The Australian pine borer (Chrysobothris tranquebarica) has on occasion devastated trees 5 years or less in age by girdling the stems (17).

The major biological cause of death of casuarina on well-drained, acid, sandy soils is a mushroom root rot (Clitocybe tabescens) (15); Casuarina cunninghamiana may be less susceptible than the other species. The incidence of root rot is reduced on wetter sites, with no evidence of the disease in alkaline soils.

Primary nonbiological losses are from lightning and frost. Killing lightning strikes are common to casuarina that are dominant in the south Florida landscape. Freezing temperatures can damage well-established trees; temperatures of approximately -8° C (18° F) kill trees less than 0.5 m (1.6 ft) in height.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Flowering and Fruiting

provided by Silvics of North America
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).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Genetics

provided by Silvics of North America
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).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Growth and Yield

provided by Silvics of North America
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.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Reaction to Competition

provided by Silvics of North America
Casuarina species are intolerant of shade but capable of rapidly invading new sites and forming pure stands. When young, trees are easily suppressed by some forms of competing vegetation, especially grasses and sedges, particularly if seedlings are not nodulated and cannot fix atmospheric nitrogen. On a well-prepared palmetto prairie in Florida, for example, newly planted casuarina seedlings failed to survive competition from wiregrass (Aristida stricta) that rapidly reinvaded the site. In the Philippines and in the Highlands of Papua, New Guinea, however, casuarina seedlings have been reported to compete aggressively against Imperata grass, a weed that makes large areas of the tropics useless for agriculture (12). Once casuarina trees dominate a site, however, their heavy root mat and the deep litter layer tend to reduce, even eliminate, competitors.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Rooting Habit

provided by Silvics of North America
Casuarina has a spreading, fibrous root system that can penetrate quite deeply into the soil if subsurface moisture is available. A very dense mat of adventitious roots may be formed in response to wet conditions. The root hairs become infected by Frankia spp. and form nitrogen-fixing nodules (18).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Seed Production and Dissemination

provided by Silvics of North America
The conelike fruits mature throughout the year, although heavier crops occur in the fall and winter. When the fruits dry from December to March, the samaras, which range in length from 3 to 8 mm (0.1 to 0.3 in), depending on species (14), are released and wind disseminated. Germination of the seeds is epigeal and good on moist, bare soil.

Seeds may be extracted readily from air-dried fruits. Cleaned seed yields range from 661,000 to 1,653,000/kg (300,000 to 750,000/lb) depending on species and location (13). Germination of seeds stored for 2 years under conditions ranging from 6 to 16 percent moisture content and -7° to 3° C (20° to 38° F) can be from 40 to 50 percent (7). No pregermination treatment is required (13). Broadcast sowing of seeds, followed by a thin topping of soil or other nursery medium sufficient to give 215 to 323 seedlings/m² (20 to 30/ft²), can result in outplantable seedlings within 3 months.

Seedling development is partly dependent on the presence of a symbiont, the filamentous actinomycete Frankia spp., which allows casuarina to fix atmospheric nitrogen. Inoculation of nursery-grown seedlings is therefore advisable. This can be accomplished by application of a 10 percent suspension of ground casuarina root nodules with water to the nursery medium (11,18).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Seedling Development

provided by Silvics of North America
Under proper conditions, growth of casuarina seedlings is extremely rapid, with growth rates of more than 2 m (6.5 ft) possible the first year. Such rates of growth are observed only when no competing herbaceous vegetation is present and may be possible only when the seedlings have been inoculated with Frankia spp., as noted earlier (11).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Soils and Topography

provided by Silvics of North America
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.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Special Uses

provided by Silvics of North America
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).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Vegetative Reproduction

provided by Silvics of North America
The three species show different levels of root suckering: C. glauca root suckers prolifically; C. cunninghamiana, infrequently; and C. equisetifolia, not at all. Rooting success, as evidenced by preliminary trials with fine branches from lower to middle portions of crowns, is satisfactory for C. cunninghamiana and C. glauca but low for C. equisetifolia. Use of rootone and a sand medium typically resulted in rooting as high as 50 percent in the spring. Grafting appears to be successful (1).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Distribution

provided by Silvics of North America
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).

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Brief Summary

provided by Silvics of North America
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.

license
cc-by-nc
copyright
USDA, Forest Service
original
visit source
partner site
Silvics of North America

Casuarina

provided by wikipedia EN

"
Fruit of C. equisetifolia
"
Casuarina sp.: cones and samaras at the Muséum de Toulouse, France

Casuarina is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in the family, but has been split into four genera (see: Casuarinaceae).[1][3]

"
Casuarina equisetifolia at Chikhaldara, India

They are evergreen shrubs and trees growing to 35 m (115 ft) tall. The slender, green to grey-green twigs bearing minute scale-leaves in whorls of 5–20. The apetalous flowers are produced in small catkin-like inflorescences. Most species are dioecious, but a few are monoecious. The fruit is a woody, oval structure superficially resembling a conifer cone, made up of numerous carpels, each containing a single seed with a small wing.[3][4] The generic name is derived from the Malay word for the cassowary, kasuari, alluding to the similarities between the bird's feathers and the plant's foliage,[5] though the tree is called rhu in current standard Malay.

Karen Louise Wilson and Lawrence Alexander Sidney Johnson distinguish the two very closely related genera, Casuarina and Allocasuarina on the basis of:[6]

  • Casuarina: the mature samaras being grey or yellow brown, and dull; cone bracteoles thinly woody, prominent, extending well beyond cone body, with no dorsal protuberance;
  • Allocasuarina: the mature samaras being red brown to black, and shiny; cone bracteoles thickly woody and convex, mostly extending only slightly beyond cone body, and usually with a separate angular, divided or spiny dorsal protuberance.

Ecology

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.

Pedunculagin, casuarictin, strictinin, casuarinin and casuariin are ellagitannins found in the species within the genus.[7]

Selected species

Sources:[1][3][10][11]

Formerly placed here

Invasive species

"
Casuarina on Gold Rock Beach, Grand Bahama

C. cunninghamiana, C. glauca and C. equisetifolia have become naturalized in several countries, including Argentina, Bermuda, Cuba, China, Egypt, Israel, Iraq, Mauritius, Kenya, Mexico, Brazil, South Africa, the Bahamas,[12] Uruguay and the southern United States; in the United States it was introduced in the early 1900s, and is now considered an invasive species.[13][14] The species has nearly quadrupled in southern Florida between 1993 and 2005, where it is known as Australian pine.[8] C. equisetifolia is widespread in the Hawaiian Islands where it grows both on the seashore in dry, salty, calcareous soils and up in the mountains in high rainfall areas on volcanic soils. It is also an invasive plant in Bermuda, where it was introduced to replace the Juniperus bermudiana windbreaks killed by a scale insect in the 1940s.[9]

References

  1. ^ a b c Australian Plant Name Index (APNI): Casuarina IBIS database. Centre for Plant Biodiversity Research, Australian Government. Retrieved 3 November 2018.
  2. ^ a b Linnaeus, C. (1759), Amoenitates Academicae 4: 143
  3. ^ a b c Flora of Australia: Casuarina
  4. ^ Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan Publishers. ISBN 0-333-47494-5.
  5. ^ Quattrocchi, Umberto (2000). CRC World Dictionary of Plant Names. I A-C. CRC Press. p. 456. ISBN 978-0-8493-2675-2.
  6. ^ Wilson, K. L.; Johnson, L. A. S. (1989). "Flora of Australia online: Casuarinaceae". ABRS, Commonwealth of Australia. Retrieved 3 November 2018.
  7. ^ Okuda, T.; T. Yoshida; M. Ashida; K. Yazaki (1983). "Tannins of Casuarina and Stachyurus species. I: Structures of pendunculagin, casuarictin, strictinin, casuarinin, casuariin, and stachyurin". Journal of the Chemical Society (8): 1765–1772.
  8. ^ a b IFAS: SRFer Mapserver Archived 2007-09-07 at the Wayback Machine
  9. ^ a b "Casuarina (Casuarina equisetifolia)". Department of Conservation. Government of Bermuda. Archived from the original on 2010-03-05. Retrieved 2010-10-01.
  10. ^ a b "GRIN Species Records of Casuarina". Germplasm Resources Information Network. United States Department of Agriculture. Archived from the original on 2009-01-20. Retrieved 2011-02-18.
  11. ^ "Casuarina". Integrated Taxonomic Information System. Retrieved 2010-02-21.
  12. ^ "Archived copy". Archived from the original on 2011-07-06. Retrieved 2008-10-04.CS1 maint: archived copy as title (link)
  13. ^ USFS FEIS: Casuarina
  14. ^ USDA Forest service: Casuarina
"
license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Casuarina: Brief Summary

provided by wikipedia EN
" Fruit of C. equisetifolia " Casuarina sp.: cones and samaras at the Muséum de Toulouse, France

Casuarina is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in the family, but has been split into four genera (see: Casuarinaceae).

" Casuarina equisetifolia at Chikhaldara, India

They are evergreen shrubs and trees growing to 35 m (115 ft) tall. The slender, green to grey-green twigs bearing minute scale-leaves in whorls of 5–20. The apetalous flowers are produced in small catkin-like inflorescences. Most species are dioecious, but a few are monoecious. The fruit is a woody, oval structure superficially resembling a conifer cone, made up of numerous carpels, each containing a single seed with a small wing. The generic name is derived from the Malay word for the cassowary, kasuari, alluding to the similarities between the bird's feathers and the plant's foliage, though the tree is called rhu in current standard Malay.

Karen Louise Wilson and Lawrence Alexander Sidney Johnson distinguish the two very closely related genera, Casuarina and Allocasuarina on the basis of:

Casuarina: the mature samaras being grey or yellow brown, and dull; cone bracteoles thinly woody, prominent, extending well beyond cone body, with no dorsal protuberance; Allocasuarina: the mature samaras being red brown to black, and shiny; cone bracteoles thickly woody and convex, mostly extending only slightly beyond cone body, and usually with a separate angular, divided or spiny dorsal protuberance.
license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN