View source for Alstonia

{{Short description|Genus of flowering plants}}
{{Automatic taxobox
|image = Alstonia scholaris.jpg
|image_caption = ''[[Alstonia scholaris]]'', habit (above), details (below)
|image2 = Alstonia.scholaris.jpg
|display_parents = 2
|taxon = Alstonia
|authority = [[Robert Brown (botanist, born 1773)|R.Br.]]
|type_species = ''[[Alstonia scholaris]]''
|type_species_authority = ([[Carl Linnaeus|L.]]) [[Robert Brown (botanist, born 1773)|R.Br.]]
|synonyms =
{{Plainlist | style = margin-left: 1em; text-indent: -1em; |
*''Amblyocalyx'' <small>Benth. in G.Bentham & J.D.Hooker</small>
*''Blaberopus'' <small>A.DC. in A.P.de Candolle</small>
*''Pala'' <small>Juss.</small>
*''Paladelpha'' <small>Pichon</small>
*''Tonduzia'' <small>Pittier</small>
*''Winchia'' <small>A.DC. in A.P.de Candolle</small>
}}
|synonyms_ref = <ref name=j>{{cite web
|url=http://apps.kew.org/wcsp/synonomy.do?name_id=6994
|title=World Checklist of Selected Plant Families
|access-date=May 21, 2014}}</ref>
}}
'''''Alstonia''''' is a widespread [[genus]] of [[evergreen]] trees and [[shrub]]s, of the family [[Apocynaceae]]. It was named by [[Robert Brown (botanist, born 1773)|Robert Brown]] in 1811, after [[Charles Alston (botanist)|Charles Alston]] (1685–1760), professor of [[botany]] at [[Edinburgh]] from 1716 to 1760.
The type species ''Alstonia scholaris'' (L.) R.Br. was originally named ''Echites scholaris'' by [[Carl Linnaeus|Linnaeus]] in 1767.
==Description==
''Alstonia'' consists of about 40–60 [[species]] (according to different authors) native to tropical and subtropical [[Africa]], [[Central America]], [[Southeast Asia]], [[Polynesia]] and [[Australia]], with most species in the [[Malesia|Malesian region]].
These trees can grow very large, such as ''Alstonia pneumatophora'', recorded with a height of 60 m and a diameter of more than 2 m. ''Alstonia longifolia'' is the only species growing in Central America (mainly shrubs, but also trees 20 m high).
The leathery, sessile, simple [[leaf|leaves]] are elliptical, ovate, linear or lanceolate and wedge-shaped at the base. The leaf blade is dorsiventral, medium-sized to large and disposed oppositely or in a whorl and with entire margin. The leaf venation is pinnate, with numerous veins ending in a marginal vein. [[Phyllotaxy]] is [[Whorl (botany)|whorled]] i.e. two or more leaves arises at a node and form a whorl .
The [[inflorescence]] is terminal or axillary, consisting of thyrsiform [[Cyme (botany)|cymes]] or compound [[umbel]]s. The small, more or less fragrant [[flower]]s are white, yellow, pink or green and funnel-shaped, growing on a pedicel and subtended by [[bract]]s. They consist of 5 [[petal]]s and 5 [[sepal]]s, arranged in four whorls. The fertile flowers are hermaphrodite. The gamosepalous green sepals consist of ovate lobes, and are distributed in one whorl. The annular disk is hypogynous. The five gamesepalous petals have oblong or ovate lobes and are disposed in one whorl. The [[Corolla (flower)|corolla]] lobes overlapping to the left (such as ''A. rostrata'') or to the right (such as ''A. macrophylla'') in the bud. The [[ovary (plants)|ovary]] has 2 separate follicles with glabrous or ciliate, oblong [[seed]]s that develop into deep blue podlike, schizocarp [[fruit]], between 7–40&nbsp;cm long. The plants contain a milky [[latex]], rich in poisonous [[alkaloid]]s. [[Fijians]] use the latex of ''A. costata'' (''saurua'', ''sorua'') as a form of [[chewing gum]].<ref>{{cite book |last1=Keppel |first1=Gunnar |title=Trees of Fiji: A Guide to 100 Rainforest Trees |last2=Ghazanfar |first2=Shahina A. |author-link2=Shahina A. Ghazanfar |date=2011 |publisher=Secretariat of the Pacific Community & Deutsche Gesellschaft für Technische Zusammenarbeit |edition=third, revised |pages=42–3}}</ref> The ''Alstonia macrophylla'' is commonly known in [[Sri Lanka]] as 'Havari nuga' or the 'wig banyan' because of its distinct flower that looks like a woman's long wig.
''Alstonia'' trees are used in [[traditional medicine]]. The bark of ''[[Alstonia constricta]]'' and ''[[Alstonia scholaris]]'' is the source of a remedy against [[malaria]], toothache, rheumatism and snake bites{{Citation needed|date=July 2008}}. The [[latex]] is used in treating coughs, throat sores and fever.
Many ''Alstonia'' species are harvested for [[timber]], called ''pule'' or ''pulai'' in Indonesia and Malaysia. Trees from the section ''Alstonia'' produce lightweight timber, while those from the sections ''Monuraspermum'' and ''Dissuraspermum'' produce heavy timber.
''Alstonia'' trees are widespread and mostly not endangered. However a few species are very rare, such as ''A. annamensis'', ''A. beatricis'', ''A. breviloba'', ''A. stenophylla'' and ''A. guangxiensis''.
==Species==
''Alstonia'' has  five distinct sections, each a [[monophyletic]] group; ''Alstonia'', ''Blaberopus'', ''Tonduzia'', ''Monuraspermum'', ''Dissuraspermum''.
;Accepted species<ref name=j/>
# ''[[Alstonia actinophylla]]'' <small>(A.Cunn.) K.Schum.</small> – milkwood - New Guinea, N Australia
# ''[[Alstonia angustifolia]]'' <small>A.DC.</small> - Borneo, W Malaysia, Sumatra
# ''[[Alstonia angustiloba]]'' <small>Miq.</small> - Borneo, W Malaysia, Sumatra, Thailand, Java
# ''[[Alstonia annamensis]]'' <small>(Monach.) K.Sidiyasa</small> - Cambodia, Vietnam
# ''[[Alstonia balansae]]'' <small>Guillaumin</small> - New Caledonia
# ''[[Alstonia beatricis]]'' <small>K.Sidiyasa</small> - Waigeo I in E Indonesia
# ''[[Alstonia boonei]]'' <small>De Wild.</small> - W + C + E Africa
# ''[[Alstonia boulindaensis]]'' <small>Boiteau</small> - New Caledonia
# ''[[Alstonia breviloba]]'' <small>K.Sidiyasa</small> - Papua New Guinea
# ''[[Alstonia congensis]]'' <small>Engl.</small> - W + C Africa
# ''[[Alstonia constricta]]'' <small>F.Muell.</small> – bitterbark, quinine tree, Australian fever bark - E Australia
# ''[[Alstonia coriacea]]'' <small>Pancher & S.Moore</small> - New Caledonia
# ''[[Alstonia costata]]'' <small>R.Br.</small> - S Pacific
# ''[[Alstonia curtisii]]'' <small>King & Gamble</small> - Thailand
# ''[[Alstonia deplanchei]]'' <small>Van Heurck & Müll.Arg.</small> - New Caledonia
# ''[[Alstonia guangxiensis]]'' <small>D.Fang & X.X.Chen</small> - Guangxi in China
# ''[[Alstonia iwahigensis]]'' <small>Elmer</small> - Borneo, Palawan
# ''[[Alstonia lanceolata]]''  <small>Van Heurck & Müll.Arg.</small> - New Caledonia
# ''[[Alstonia lanceolifera]]'' <small>S.Moore</small> - New Caledonia
# ''[[Alstonia legouixiae]]'' <small>Van Heurck & Müll.Arg.</small> - New Caledonia
# ''[[Alstonia lenormandii]]'' <small>Van Heurck & Müll.Arg.</small> - New Caledonia
# ''[[Alstonia longifolia]]'' <small>(A.DC.) Pichon</small> - Mexico, Central America
# ''[[Alstonia macrophylla]]'' <small>Wall. ex G.Don</small> – batino, devil tree - S China, Sri Lanka, SE Asia, New Guinea
# ''[[Alstonia mairei]]'' <small>H. Léveillé</small> - S China, N Vietnam
# ''[[Alstonia muelleriana]]'' <small>Domin</small> – jackapple, leatherjacket, milky yellowwood - New Guinea, Queensland
# ''[[Alstonia neriifolia]]'' <small>D.Don</small> - Nepal, Sikkim, Bhutan
# ''[[Alstonia odontophora]]'' <small>Boiteau</small> - New Caledonia
# ''[[Alstonia parkinsonii]]'' <small>(M.Gangop. & Chakrab.) Lakra & Chakrab.</small> - Andaman Is.
# ''[[Alstonia parvifolia]]'' <small>Merr.</small> - Philippines
# ''[[Alstonia penangiana]]'' <small>K.Sidiyasa</small> - Penang Hill in Malaysia
# ''[[Alstonia pneumatophora]]'' <small>Backer ex L.G.Den Berger</small> - W Malaysia, Borneo, Sulawesi, Sumatra
# ''[[Alstonia quaternata]]'' <small>Van Heurck & Müll.Arg. -</small> New Caledonia
# ''[[Alstonia rostrata]]'' <small>C.E.C.Fischer</small> - Yunnan, Indochina, W Malaysia, Sumatra
# ''[[Alstonia rubiginosa]]'' <small>K.Sidiyasa</small> - Papua New Guinea
# ''[[Alstonia rupestris]]'' <small>Kerr</small> - Thailand
# ''[[Alstonia scholaris]]'' <small>(L.) R.Br.</small> – pali-mari, dita bark, bitter bark, milkwood, milky bean, milky pine, white cheesewood, scholar tree, blackboard tree - E + S + SE Asia, Papuasia, N Australia
# ''[[Alstonia sebusii]]'' <small>(Van Heurck & Müll.Arg.) Monach.</small> - Yunnan, Bhutan, Assam, N Myanmar
# ''[[Alstonia spatulata]]'' <small>Blume</small> – hard milkwood, Siamese balsa - SE Asia, New Guinea
# ''[[Alstonia spectabilis]]'' <small>R.Br.</small> – poele bark, jackapple, leatherjacket, milky yellowwood - SE Asia, Papuasia, N Australia
# ''[[Alstonia sphaerocapitata]]'' <small>Boiteau</small> - New Caledonia
# ''[[Alstonia venenata]]'' <small>R.Br.</small> - S India
# ''[[Alstonia vieillardii]]'' <small>Van Heurck & Müll.Arg.</small> - New Caledonia
# ''[[Alstonia vietnamensis]]'' <small>D.J.Middleton</small> - Vietnam
# ''[[Alstonia yunnanensis]]'' <small>Diels</small> - Yunnan, Guizhou, Guangxi
==Gallery==
<gallery>
Alstonia scholaris (Saptaparni) in Hyderabad, AP W IMG 1469.jpg|''[[Alstonia scholaris]]''
Alstonia spectabilis Blanco2.379.png|''[[Alstonia spectabilis]]''
Alstonia macrophylla (Batino) in Hyderabad W IMG 7138.jpg|''[[Alstonia macrophylla]]''
</gallery>
==Notes==
{{Reflist}}
==References==
{{Commons category|Alstonia}}
* {{cite journal|author=Kade Sidiyasa|title= Taxonomy, phylogeny, and wood anatomy of Alstonia (Apocynaceae)|journal=Blumea. Supplement|volume= 11|date=1998|pages=1–230|url=http://www.repository.naturalis.nl/document/566777}}  {{ISBN|90-71236-35-8}}
* Kade Sidiyasa, A., 3, 1992. A monograph of Alstonia (Apocynaceae).
* {{cite journal|last1=Forster|first1=P.I.|title=A taxonomic revision of Alstonia (Apocynaceae) in Australia|journal=Australian Systematic Botany|volume=5|issue=6|year=1992|pages=745|issn=1030-1887|doi=10.1071/SB9920745}}
{{Taxonbar|from=Q2475725}}
{{Authority control}}
[[Category:Alstonia| ]]
[[Category:Apocynaceae genera]]
[[Category:Taxa named by Robert Brown (botanist, born 1773)]]