Alstonia scholaris
{{Short description|Species of flowering plant}}
{{Use dmy dates|date=April 2025}}
{{Use British English|date=April 2025}}
{{Speciesbox
|image = Alstonia scholaris.jpg
|image_caption =
|status = LC
|status_system = IUCN3.1
|genus = Alstonia
|species = scholaris
|authority = (L.) R.Br.{{R|POWO}}
|range_map = Alstoniascholaris1.png
|range_map_caption = Occurrence data from GBIF{{GBIF|title=Alstonia scholaris (L.) R.Br. |id=5414410 |access-date=22 April 2025}}
|synonyms = {{collapsible list|{{species list
|Echites scholaris |L.
|Nerium septaparna |Jones
|Pala scholaris |(L.) Roberty
|Alstonia kurzii |Hook.f.
|Alstonia scholaris var. avae |A.DC.
|Alstonia scholaris var. blumei |A.DC.
|Alstonia scholaris var. velutina |Monach.
|Alstonia spectabilis |Kurz
|Echites pala |Buch.-Ham. ex Spreng.
|Aeschynomene laevis |Noronha
}} }}
|synonyms_ref = {{R|POWO}}
}}
Alstonia scholaris, commonly called blackboard tree, scholar tree, milkwood or devil's tree in English,{{GRIN |access-date=2012-03-30}} is an evergreen tree in the oleander and frangipani family Apocynaceae. Its natural range is from Pakistan to China, and south to northern Australia. It is a toxic plant, but is used traditionally for myriad diseases and complaints. It is called 'Saptaparna' in India and is the sacred tree of the 2nd Jain tirthankar Ajitnatha.{{Not verified in body|date=April 2025}} It was first described by Linnaeus in 1767, who gave it the name Echites scholaris.
Description
Alstonia scholaris is a large tree growing up to {{cvt|40|m}} tall (rarely to 60 m), with narrow buttressess that extend well up the trunk, giving it a fluted appearance. The bark is gray to pale gray with numerous lenticels, and all parts of the plant exude copious amounts of white sap when broken or cut.{{R|FOA|FOC|NPSING|RFK|ORWA}}{{excessive citations inline|date=April 2025}}
The leaves are glossy dark green above and pale below, and they are arranged in whorls of four to eight, with petioles (leaf stalks) around {{cvt|5-15|mm|2}} long. The leaves are usually obovate (i.e. broadest near the apex) to elliptic, tapering towards the base and with a rounded tip, and there are 25 to 40 pairs of lateral veins at 80–90° to the midvein.{{R|FOA|FOC|NPSING|RFK|ORWA}}{{excessive citations inline|date=April 2025}}
The inflorescences are much branched ({{botanygloss|cyme|cymose}}), with peduncles up to {{cvt|7|cm|1}} long, and are produced at the ends of the branches. The small tubular flowers are cream or white and strongly scented. They are about {{cvt|10|mm|2}} long and wide, with five {{botanygloss|ovate}} lobes. The calyx is about {{cvt|2|mm|2}} long, and the flower stalks are usually as long as or shorter. The corolla is white and tube-like, {{convert|6–10|mm|abbr=on|sigfig=1}} long. The lobes are broadly ovate or broadly obovate, {{convert|2-4.5|mm|abbr=on|sigfig=1}}, overlapping to the left.{{R|FOA|FOC|NPSING|RFK|ORWA}}{{excessive citations inline|date=April 2025}}
The fruit is a pair of long papery follicles measuring up to about {{cvt|30|cm}} long and {{cvt|6|mm|2}} diameter. They contain numerous flat, brown seeds about {{cvt|5|mm|2}} long and {{cvt|1.2|mm|2}} wide, which have long tufts of hairs at each end.{{R|FOA|FOC|NPSING|RFK|ORWA}}{{excessive citations inline|date=April 2025}}
Taxonomy
This plant was originally named Echites scholaris by Carl Linnaeus in 1767.{{R|POWO|LINNEAUS}} The Scottish botanist Robert Brown transferred it to the genus Alstonia in 1810, as part of his work on the taxonomy of Apocynaceae.{{R|BROWN}}
=Etymology=
The genus was named in honour of botanist Charles Alston, and the species epithet scholaris is a reference to the traditional use of the timber of this tree for blackboards in Myanmar.{{R|ORWA}}
Distribution and habitat
Alstonia scholaris grows in a broad range of habitats in tropical and subtropical areas, in a range of forest types from rainforest to savannah, on a variety of soils including alluviall, volcanic and metamorphic, and at altitudes from sea level to more than {{cvt|1000|m}}.{{R|FOC|NPSING|RFK|ORWA}}
The tree is native to tropical and subtropical areas in the following countries/regions:
- China: Guangxi, Yunnan
- Indian subcontinent: Assam, Bangladesh, Bhutan, East Himalaya, India, Laccadive Is., Nepal, Pakistan, Sri Lanka, West Himalaya
- Indo-China: Andaman Is., Cambodia, Laos, Myanmar, Nicobar Is., South China Sea, Thailand, Vietnam
- Malesia: Borneo, Indonesia, Java, Lesser Sunda Is., Malaysia, Maluku, Philippines, Sulawesi, Sumatera,
- Papuasia: Bismarck Archipelago, New Guinea, Solomon Islands
- Australia: Northern Territory, Queensland, Western Australia
Toxicity
This is a toxic plant. At high doses, an extract of the plant exhibited marked damage to all the major organs of the body in both rats and mice. The toxicity appears to depend on the plant organ studied, as well as the season it is harvested, with the bark collected in the monsoon season being the least toxic, and bark in the summer the most. Intraperitoneal administration is much more toxic than oral. Rats were more susceptible to the poison than mice, and pure-bred mice strains were more susceptible than crossbred. The toxic effects may be due to the alkaloid echitamine in the bark.{{cite journal |last1=Baliga |first1=Manjeshwar Shrinath |last2=Jagetia |first2=Ganesh Chandra |last3=Ulloor |first3=Jagadish N. |last4=Baliga |first4=Manjeshwar Poonam |last5=Ponemone |first5=Venkatesh |last6=Reddy |first6=Rosi |last7=Rao |first7=Mallikarjun K. V. N. |last8=Baliga |first8=Shivanada Bantwal |last9=Devi |first9=Sulochana |last10=Raju |first10=Sudheer Kumar |last11=Veeresh |first11=Veerapura |last12=Reddy |first12=Tiyyagura Koti |last13=Bairy |first13=Laxminarayana K. |date=2004 |title=The evaluation of the acute toxicity and long term safety of hydroalcoholic extract of Sapthaparna (Alstonia scholaris) in mice and rats |url=http://eprints.manipal.edu/314 |journal=Toxicology Letters |volume=151 |issue=2 |pages=317–326 |doi=10.1016/j.toxlet.2004.01.015|pmid=15183456 |url-access=subscription }}
=Chemistry=
The bark contains the alkaloids ditamine, echitenine,{{cite journal |title=The evaluation of the acute toxicity and long term safety of hydroalcoholic extract of Sapthaparna (Alstonia scholaris) in mice and rats |date=2004 |last1=Baliga |first1=M. |last2=Jagetia |first2=G. C. |last3=Ulloor |first3=J. N. |last4=Baliga |first4=M. P. |last5=Venkatesh |first5=P. |last6=Reddy |first6=R. |last7=Rao |first7=K. V. |last8=Baliga |first8=B. S. |last9=Devi |first9=S. |last10=Raju |first10=S. K. |last11=Veeresh |first11=V. |last12=Reddy |first12=T. K. |last13=Bairy |first13=K. L. |journal=Toxicology Letters |volume=151 |issue=2 |pages=317–326 |doi=10.1016/j.toxlet.2004.01.015 |pmid=15183456 }} echitamine and strictamine.{{cite journal | pmid = 500142 | year = 1979 | last1 = Bhattacharya | first1 = S. K. | title = Neuropharmacological studies on strictamine isolated from Alstonia scholaris | journal = Indian Journal of Experimental Biology | volume = 17 | issue = 6 | pages = 598–600 | last2 = Bose | first2 = R. | last3 = Dutta | first3 = S. C. | last4 = Ray | first4 = A. B. | last5 = Guha | first5 = S. R. }} Echitamine is the most important alkaloid found in the bark, as it has been detected in all samples studied and collected from several locations. It is commercially sold as a herbal medicine.{{cite journal |last1=Yamauchi |first1=Tatsuo |last2=Abe |first2=Fumiko |last3=Padolina |first3=William G. |last4=Dayrit |first4=Fabian M. |date=1990 |title=Alkaloids from leaves and bark of Alstonia scholaris in the Philippines |url=https://www.academia.edu/7426110 |journal=Phytochemistry |volume=29 |issue=10 |pages=3321–3325 |doi=10.1016/0031-9422(90)80208-X |bibcode=1990PChem..29.3321Y |access-date=1 July 2021}}
Culture
Alstonia scholaris is the state tree of West Bengal, India, where it is called Chhatim tree.{{Citation needed|date=April 2025}}
During convocation the leaves of Alstonia scholaris (saptaparni) are awarded to graduates and postgraduates of Visva-Bharati University by the chancellor, given to him in turn by the Prime Minister of India. In recent years, supposedly to prevent excessive damage to the environment, the vice-chancellor of the University accepts one saptaparni leaf from the chancellor on behalf of all the students. This tradition was initiated by the founder of the University, Rabindranath Tagore.{{cite news | author = Abhishek Gulshan | date = 22 October 2019 | title = Why the Saptaparni is called the devil's tree | url = https://www.thehindu.com/sci-tech/energy-and-environment/why-the-saptaparni-is-called-the-devils-tree/article29767114.ece | newspaper = The Hindu | access-date = 14 February 2023}}
Uses
The wood of Alstonia scholaris has been recommended for the manufacture of pencils, as it is suitable in nature and the tree grows rapidly and is easy to cultivate.Tonanont, N. Wood used in pencil making. Vanasarn 1974 Vol. 32 No. 3 pp. 225–227 In Sri Lanka its light wood was used for coffins. The wood close to the root is very light and of white colour, and in Borneo was used for net floats, household utensils, trenchers, corks, etc.{{cite book|chapter-url=http://www.botanical.com/botanical/mgmh/a/alsto028.html |last=Grieve |first=M. |chapter=Alstonia |title=A Modern Botanical |date=1931 |location= |publisher= |access-date=29 June 2007}} In Theravada Buddhism, the first Buddha is said to have used A. scholaris as the tree for achieving enlightenment.
The 1889 book The Useful Native Plants of Australia states that "the powerfully bitter bark of this tree is used by the natives of India in bowel complaints (Treasury of Botany). It has proved a valuable remedy in chronic diarrhoea and the advanced stages of dysentery. It has also been found effectual in restoring the tone of the stomach and of the system generally in debility after fevers and other exhausting diseases (Pharmacopoeia of India). It is described in the Pharmacopoeia of India as an astringent tonic, anthelmintic, and antiperiodic. It is held in the highest repute in the Phillippine Islands [sic]."{{cite book | author=J. H. Maiden | year=1889 | title=The useful native plants of Australia : Including Tasmania |location=Sydney | publisher=Turner and Henderson | url=https://primo-slnsw.hosted.exlibrisgroup.com/primo-explore/fulldisplay?docid=SLNSW_ALMA21105097830002626&context=L&vid=SLNSW&search_scope=EEA&tab=default_tab&lang=en_US}} Despite its widespread traditional use as an 'antiperiodic' (a medicine which was supposed to cure the effects of malaria), it was found to have little to very weak activity against the cause of the disease, Plasmodium falciparum.{{cite journal |last1=Wright |first1=Colin W. |last2=Allen |first2=David |last3=Phillipson |first3=J. David |last4=Kirby |first4=Geoffrey C. |last5=Warhurst |first5=David C. |last6=Massiot |first6=Georges |last7=Le Men-Olivier |first7=Louisette |date=September 1993 |title=Alstonia species: are they effective in malaria treatment? |journal=Journal of Ethnopharmacology |volume=40 |issue=1 |pages=41–45 |doi=10.1016/0378-8741(93)90087-L|pmid=8246529 }}{{cite journal |last1=Wright |first1=C. W. |last2=Allen |first2=D. |last3=Cai |first3=Ya |last4=Phillipson |first4=J. D. |last5=Said |first5=I. M. |last6=Kirby |first6=G. C. |last7=Warhurst |first7=D. C. |date=June 1992 |title=In vitro antiamoebic and antiplasmodial activities of alkaloids isolated from Alstonia angustifolia roots |journal=Phytotherapy Research |volume=6 |issue=3 |pages=121–124 |doi=10.1002/ptr.2650060303|s2cid=86802484 }} It had no effect against Giardia intestinalis, and weak effect against Entamoeba histolytica, which both cause diarrhoea.
Gallery
{{gallery |mode=packed
|File:Alstonia-scholaris-SF24353-01.jpg |Mature tree in Cairns, Queensland
|File:Alstonia scholaris 01.JPG|Trunk of a large tree
|File:Alstonia-scholaris-SF22086-6.jpg|Fluted trunk
|Image:Alstonia scholaris by kadavoor.JPG |Arrangement of leaves
|File:Alstonia - Kolkata 2011-10-20 5923.JPG |Flowers
|File:Devil Tree - Alstonia scholaris - ഏഴിലം പാല 04.jpg |Fruit
|File:Alstonia scholaris seed.jpg |Seed
|File:Alstonia.scholaris.jpg |Botanical illustration
}}
References
{{Reflist|refs=
{{cite web |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:60445977-2 |title=Alstonia scholaris (L.) R.Br. |website=Plants of the World Online |publisher=Board of Trustees of the Royal Botanic Gardens, Kew |year=2025 |access-date=22 April 2025}}
{{cite web |title=Alstonia scholaris (L.) R.Br. |url=https://www.nparks.gov.sg/florafaunaweb/flora/2/7/2705 |website=Flora and Fauna Web |publisher=Singapore Government |access-date=23 April 2025 }}
{{cite web |url=https://profiles.ala.org.au/opus/foa/profile/Alstonia%20scholaris |title=Alstonia scholaris |last1=Forster |first1=P.I. |year=2022 |website=Flora of Australia |publisher=Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra |access-date=23 April 2025}}
{{cite web |url=https://apps.lucidcentral.org/rainforest/text/entities/Alstonia_scholaris.htm |title=Alstonia scholaris |author1=F.A.Zich |author2=B.P.M.Hyland |author3=T.Whiffen |author4=R.A.Kerrigan |author2-link=Bernard Hyland |year=2020 |website=Australian Tropical Rainforest Plants Edition 8 (RFK8) |publisher=Centre for Australian National Biodiversity Research (CANBR), Australian Government |access-date=23 April 2025}}
}}
{{Taxonbar|from=Q135307}}
Category:Flora of tropical Asia
Category:Gentianales of Australia
Category:Least concern flora of Australia