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Alstonia breviloba

Overview

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Vulnerable

Threat status

Interesting Facts

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Description

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Family Apocynaceae

Trees , shrubs , or vines , rarely subshrubs or herbs, with latex or rarely watery juice. Leaves simple , opposite, rarely whorled or alternate, pinnately veined; stipules absent or rarely present. Inflorescences cymose , terminal or axillary , with bracteoles. Flowers bisexual , 5- [or 4]-merous, actinomorphic . Calyx 5- or rarely 4-partite, quincuncial, basal glands usually present. Corolla 5- or rarely 4-lobed, salverform , funnelform , urceolate , or rarely rotate, lobes overlapping to right or left, rarely valvate . Stamens 5 or rarely 4; filaments short; anthers mostly sagittate , free or connivent into a cone adherent to pistil head , dehiscing longitudinally, base rounded , cordate, sagittate, or prolonged into an empty spur; pollen granular ; disc ringlike or cup-shaped, 2-5-lobed, or absent. Ovaries superior, rarely half-inferior, connate or distinct , 1- or 2-locular; ovules (1 or) 2-numerous per locule. Style 1; pistil head capitate, conical , or lampshade-shaped, base stigmatic, apex 2-cleft and not stigmatic . Fruit a berry, drupe, capsule, or follicle. Seeds with or without coma; endosperm thick and often horny , scanty, sometimes absent; embryo straight or nearly so, cotyledons often large, radicle terete .

About 155 genera and 2000 species distributed primarily in the tropics and subtropics, poorly represented in the temperate regions . Of the 44 genera and 145 species present in China, one genus and 38 species are endemic, and nearly 95% of the taxa grow in the southern and southwestern portions of the country.

Fruit type is highly diversified in the family , and it is diagnostic of many genera. Genera 1-4 produce 1, 2-celled berries from a flower; genus 5 produces 2, 1-celled berries from a flower; 6 and 7 produce mostly fleshy follicles containing deeply indented seeds with ruminate endosperm; 8 has follicles and winged seeds; 9 produces follicles and seeds with 2 comas; 10-12 have follicles with globose seeds; 13-18 have drupes mostly with fleshy mesocarp; 19 has samaroid fruit; 20 has spiny capsules with seeds winged all around; and 21-44 have free or fused follicles and comose seeds. Double flowers are known only from cultivated forms of Nerium oleander, Tabernaemontana divaricata, and Wrightia religiosa.

Plants of the Apocynaceae are often poisonous and are rich in alkaloids or glycosides, especially in the seeds and latex. Some species are valuable sources of medicine, insecticides , fibers, and rubber.[1]

Genus Alstonia

Trees or shrubs , latex present. Branches whorled , mostly 4 or 5 together. Leaves whorled, rarely opposite; lateral veins numerous , ending in a marginal vein . Cymes terminal , usually 1-5 in thyrses or compound umbels, terminal. Flowers white, yellow, or pink. Calyx without glands inside, lobes connate at base . Corolla salverform , tube cylindric , dilated in distal half, pubescent inside, lobes overlapping to right or left. Stamens included , inserted near or above middle of corolla tube; anthers ovate , free from pistil head , not caudate ; disc absent or of scales . Ovaries 2, distinct or connate, ovules numerous. Follicles 2, free or connate. Seeds oblong or linear , long bearded at both ends; endosperm thin; cotyledons up to twice as long as radicle.

About 60 species: tropical Asia, Africa, C America, N Australia, Pacific Islands; eight species in China.[2]

Habitat

Biome: Terrestrial [3].

Ecology: The species occurs in secondary and primary montane forest . (Ref. 252915).

Taxonomy

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Notes

Publishing author : Sidiy. Publication : Blumea, Suppl. 11: 118 1998

Similar Species

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Members of the genus Alstonia

ZipcodeZoo has pages for 6 species, subspecies, varieties, forms, and cultivars in this genus:

A. angustiloba (Pulai Tree) · A. constricta (Australian Feverbark-Tree) · A. macrophylla (Devil Tree) · A. scholaris (Blackboard Tree) · A. spathulata (Hard Milkwood) · A. spatulata (Hard Milkwood)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal January 12, 2008:

Identifiers

Footnotes

  1. Bingtao Li, Antony J. M. Leeuwenberg & David J. Middleton "Apocynaceae". in Flora of China Vol. 16 Page 143. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. "Alstonia". in Flora of China Vol. 16 Page 154. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  3. World Conservation Monitoring Centre 1998. Alstonia breviloba. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 30 January 2012. [back]
Last Revised: 7/22/2012