Casuarinaceae 

{{Short description|Family of plants}}

{{Automatic taxobox

| image = Equisetoid_twigs.jpg

| image_caption = Common ironwood (Casuarina equisetifolia)

| taxon = Casuarinaceae

| authority = R.Br.{{Cite journal | author= Angiosperm Phylogeny Group | year= 2009 | title= An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III | journal= Botanical Journal of the Linnean Society | volume= 161 | issue= 2 | pages= 105–121 | doi= 10.1111/j.1095-8339.2009.00996.x | doi-access= free }}

| type_genus = Casuarina

| type_genus_authority = L.

| subdivision_ranks = Genera

| subdivision = *Allocasuarina L.A.S.Johnson 1982

• Casuarina L. 1759
• Ceuthostoma L.A.S.Johnson 1986
• Gymnostoma L.A.S.Johnson 1980

| range_map = Casuarinaceae distribution.svg

| range_map_caption = The range of Casuarinaceae

}}

The Casuarinaceae are a family of dicotyledonous flowering plants placed in the order Fagales, consisting of four genera and 91 species{{cite journal |author1=Christenhusz, M. J. M. |author2=Byng, J. W. | year = 2016 | title = The number of known plants species in the world and its annual increase | journal = Phytotaxa | volume = 261 | pages = 201–217 | url = http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 | doi = 10.11646/phytotaxa.261.3.1 | issue = 3 | doi-access = free |bibcode=2016Phytx.261..201C }} of trees and shrubs native to eastern Africa, Australia, Southeast Asia, Malesia, Papuasia, and the Pacific Islands. At one time, all species were placed in the genus Casuarina. Lawrence Alexander Sidney Johnson separated out many of those species and renamed them into the new genera of Gymnostoma in 1980 and 1982, Allocasuarina in 1982, and Ceuthostoma in 1988, with some additional formal descriptions of new species in each other genus. At the time, it was somewhat controversial. The monophyly of these genera was later supported in a 2003 phylogenetic study of the family. In the Wettstein system, this family was the only one placed in the order Verticillatae. Likewise, in the Engler, Cronquist, and Kubitzki systems, the Casuarinaceae were the only family placed in the order Casuarinales.

Members of this family are characterized by drooping equisetoid (meaning "looking like Equisetum"; that is, horsetail) twigs, evergreen foliage, monoecious or dioecious and infructescences ('fruiting bodies') strobiloid or cone-like, meaning combining many outward-pointing valves, each containing a seed, into roughly spherical, cone-like, woody structures. The roots have nitrogen-fixing nodules that contain the soil actinomycete Frankia.{{cite journal |vauthors=Zhong C, Mansour S, Nambiar-Veetil M, Bogusz D, Franche C |title=Casuarina glauca: a model tree for basic research in actinorhizal symbiosis |journal=J Biosci |volume=38 |issue=4 |pages=815–23 |date=2013 |doi=10.1007/s12038-013-9370-3 |pmid=24287661|s2cid=2232664 }}

In Australia, the most widely used common name for Casuarinaceae species is sheoak or she-oak (a comparison of the timber quality with English oak). Other common names in Australia include ironwood, bull-oak or buloke, beefwood,{{cite book |last1=Cox |first1=P. |last2=Freeland |first2=J. |date=1969 |title=Rude timber buildings in Australia |publisher=Thames and Hudson |isbn=0-500-34035-8 |page=18}} Cox states that the name 'she-oak' is derived from Native America sheac — beefwood. or cassowary tree.{{Cite book | last= Partridge | first= Eric | title= Origins: A Short Etymological Dictionary of Modern English | year= 2013 | publisher= Routledge | isbn= 9781134942176 | page= 82 | url= https://books.google.com/books?id=9fbpc7iyL2UC&pg=PA82 }}

The Shire of Buloke in Victoria, Australia, is named after the species Allocasuarina luehmannii.