Alstonia

Alstonia
Indian Devil tree (Alstonia scholaris)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Gentianales
Family:	Apocynaceae
Tribe:	Plumeriae
Subtribe:	Alstoniinae
Genus:	Alstonia R.Br.
Species
See text.

Alstonia macrophylla in Hyderabad, India.

Bitter Bark (Alstonia scholaris)

Alstonia spectabilis

Alstonia is a widespread genus of evergreen trees and shrubs from the dogbane family (Apocynaceae). It was named by Robert Brown in 1811, after Charles Alston (1685-1760), Professor of botany at Edinburgh from 1716-1760.

The type species Alstonia scholaris (L.) R.Br. was originally named Echites scholaris by Linnaeus in 1767.

Description

Alstonia (devil tree) 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 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 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.

Alstonia scholaris in Hyderabad, India.

The inflorescence is terminal or axillary, consisting of thyrsiform cymes or compound umbels. The small, more or less fragrant flowers are white, yellow, pink or green and funnel-shaped, growing on a pedicel and subtended by bracts. They consist of 5 petals and 5 sepals, 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 lobes overlapping to the left (such as A. rostrata) or to the right (such as A. macrophylla) in the bud. The ovary has 2 separate follicles with glabrous or ciliate, oblong seeds that develop into deep blue podlike, schizocarp fruit, between 7-40 cm long. The plants contain a milky sap, rich in poisonous alkaloids. 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 the Alstonia constricta and the Alstonia scholaris is a source of a remedy against malaria, toothache, rheumatism and snake bites. The latex is used in treating coughs, throat sores and fever.

Many Alstonia species are commercial timbers, called pule or pulai in Indonesia and Malaysia. Trees from the section Alstonia produce light 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.

• Alstonia actinophylla (A.Cunn.) K.Schum. - Milkwood
• Alstonia acuminata Miq.
• Alstonia annamensis ( Monach. ) K.Sidiyasa
• Alstonia angustifolia A.DC.
• Alstonia balansae Guillaumin
• Alstonia beatricis K.Sidiyasa
• Alstonia boonei De Wild.
• Alstonia boulindaensis Boiteau
• Alstonia brassii Monachino
• Alstonia breviloba K.Sidiyasa
• Alstonia calophylla Miq.
• Alstonia comptonii S.Moore
• Alstonia congensis Engl.
• Alstonia constricta F.Muell. - Bitterbark, Quinine Tree, Australian Fever Bark
• Alstonia coriacea Pancher & S.Moore
• Alstonia costata R.Br.
• Alstonia cuneata Wall. & G.Don
• Alstonia curtisii King & Gamble
• Alstonia deplanchei Van Heurck & Müll.Arg.
• Alstonia duerckheimianan Schltr.
• Alstonia edulis G.Benn.
• Alstonia elliptica J.W.Moore
• Alstonia esquirolii H.Lév.
• Alstonia eximia Miq.
• Alstonia ficifolia S.Moore
• Alstonia filipes Schltr. ex Guillaumin
• Alstonia fragrans J.W.Moore
• Alstonia gilletii De Wild.
• Alstonia glabriflora Markgr.
• Alstonia godeffroyi Reinecke
• Alstonia grandifolia Miq.
• Alstonia guangxiensis D.Fang & X.X.Chen
• Alstonia henryi Tsiang
• Alstonia iwahigensis Elmer
• Alstonia kurzii Hook.f.
• Alstonia lanceolata Van Heurck & Müll.Arg.
• Alstonia lanceolifera S.Moore
• Alstonia legouixiae Van Heurck & Müll.Arg.
• Alstonia lenormandii Van Heurck & Müll.Arg.
• Alstonia linearifolia Guillaumin
• Alstonia linearis Benth.
• Alstonia longifolia (A.DC.) Pichon
• Alstonia longissima F.Muell.
• Alstonia macrophylla Wall. ex G.Don - Batino, Devil Tree
• Alstonia mairei H. Léveillé
• Alstonia marquisensis M.L.Grant ex Fosberg & Sachet
• Alstonia micrantha Ridl.
• Alstonia mollis Benth.
• Alstonia montana Turrill
• Alstonia muelleriana Domin - Jackapple, Leatherjacket, Milky Yellowwood
• Alstonia paupera (synonym of A. mairei)
• Alstonia penangiana K.Sidiyasa
• Alstonia plumosa Labill.
• Alstonia pneumatophora Backer ex L.G.Den Berger
• Alstonia polyphylla Miq.
• Alstonia quaternata Van Heurck & Müll.Arg.
• Alstonia reineckeana Lauterb.
• Alstonia retusa S.Moore
• Alstonia roeperi Van Heurck & Müll.Arg.
• Alstonia rostrata C.E.C.Fischer
• Alstonia rubiginosa K.Sidiyasa
• Alstonia rupestris Kerr
• Alstonia saligna S.Moore
• Alstonia scholaris (L.) R.Br. - Pali-mari, Dita Bark, Bitter Bark, Milkwood, Milky Bean, Milky Pine, White Cheesewood, Blackboard Tree
• Alstonia sericea Blume
• Alstonia setchelliana Christoph.
• Alstonia smithii Markgr.
• Alstonia somersetensis F.M.Bailey
• Alstonia spathulifolia Guillaumin
• Alstonia spatulata Blume - Hard Milkwood, Siamese Balsa
• Alstonia spectabilis R.Br. - Poele Bark, Jackapple, Leatherjacket, Milky Yellowwood
• Alstonia sphaerocapitata Boiteau
• Alstonia stenophylla Guillaumin
• Alstonia subsessilis Miq.
• Alstonia twahigensis
• Alstonia undulata Guillaumin
• Alstonia undulifolia K.M.Kochummen & K.M.Wong
• Alstonia venenata R.Br.
• Alstonia verticillosa F.Muell.
• Alstonia vieillardii Van Heurck & Müll.Arg.
• Alstonia villosa Blume
• Alstonia vitiensis Seem.
• Alstonia yunnanensis Diels

References

• Kade Sidiyasa. Taxonomy, phylogeny, and wood anatomy of Alstonia (Apocynaceae). 230 pp. Blumea, Suppl. 11 (1998), ISBN 90-71236-35-8. (Awarded with the Engler Medal by the International Association for Plant Taxonomy)
• Kade Sidiyasa, A., 3, 1992. A monograph of Alstonia (Apocynaceae).
• Forster, Paul I. - A taxonomic revision of Alstonia (Apocynaceae) in Australia (1992)