Belongs within: Apocynaceae.
The Aspidospermeae are a tribe within the family Apocynaceae that was defined by Sennblad & Bremer (2002) as the most inclusive clade including Aspidosperma and Vallesia but not the Alyxieae, Carisseae, Hunterieae, Melodineae, Plumerieae, Tabernaemontaneae, Vinceae, Willughbieae or Apocynoidina. Members of this clade include herbs, shrubs and trees; some of the latter in the genera Aspidosperma and Alstonia are commercial timber sources. Fruits are drupes in Vallesia but follicles in other genera.
Synapomorphies (Sennblad & Bremer 2002): Style heads simple, lacking both stigmatic hollow and upper hair wreath; fruits apocarpous.
<==Aspidospermeae [Alstonieae]
| i. s.: GeissospermumSB02
| HaplophytonSB02
| MicroplumeriaSB02
| StrempeliopsisSB02
|--+--Vallesia antillanaSB02
| `--AspidospermaSB02
| |--A. gomezianumC55
| |--A. megalocarponSK02
| |--A. polyneuronF04
| |--A. tomentosumRJ11
| `--A. triternatumSB02
`--AlstoniaSB02
|--A. actinophyllaLK14
|--A. angustifoliaK03
|--A. booneiSK02
|--A. constrictaH42
|--A. linearisLK14
|--A. macrophyllaT-W89
|--A. muellerianaBH07
|--A. scholarisSB02
|--A. spatulataC78
|--A. spectabilisLK14
`--A. verticallosaH42
*Type species of generic name indicated
References
[BH07] Brock, P. D. & J. W. Hasenpusch. 2007. Studies on the Australian stick insects (Phasmida), including a checklist of species and bibliography. Zootaxa 1570: 1–81.
[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 1. Librairie de Victor Masson: Paris.
[C78] Clunie, N. M. U. 1978. The vegetation. In: Womersley, J. S. (ed.) Handbooks of the Flora of Papua New Guinea vol. 1 pp. 1–11. Melbourne University Press: Carlton South (Australia).
[F04] Fitzpatrick, J. W. 2004. Family Tyrannidae (tyrant-flycatchers). In: Hoyo, J. del, A. Elliott & D. A. Christie (eds) Handbook of the Birds of the World vol. 9. Cotingas to pipits and wagtails pp. 170–462. Lynx Edicions: Barcelona.
[H42] Hill, G. F. 1942. Termites (Isoptera) from the Australian Region (including Australia, New Guinea and islands south of the Equator between 140°E. longitude and 170°W. longitude). Commonwealth of Australia Council for Scientific and Industrial Research: Melbourne.
[K03] Kulip, J. 2003. An ethnobotanical survey of medicinal and other useful plants of Muruts in Sabah, Malaysia. Telopea 10 (1): 81–98.
[LK14] Lyons, M. N., G. J. Keighery, L. A. Gibson & T. Handasyde. 2014. Flora and vegetation communities of selected islands off the Kimberley coast of Western Australia. Records of the Western Australian Museum Supplement 81: 205–244.
[RJ11] Rising, J. D., A. Jaramillo, J. L. Copete, P. G. Ryan & S. C. Madge. 2011. Family Emberizidae (buntings and New World sparrows). In: Hoyo, J. del, A. Elliott & D. A. Christie (eds) Handbook of the Birds of the World vol. 16. Tanagers to New World Blackbirds pp. 428–683. Lynx Edicions: Barcelona.
[SB02] Sennblad, B., & B. Bremer. 2002. Classification of Apocynaceae s.l. according to a new approach combining Linnaean and phylogenetic taxonomy. Systematic Biology 51 (3): 389–409.
[SK02] Struwe, L., J. W. Kadereit, J. Klackenberg, S. Nilsson, M. Thiv, K. B. von Hagen & V. A. Albert. 2002. Systematics, character evolution, and biogeography of Gentianaceae, including a new tribal and subtribal classification. In: Struwe, L., & V. A. Albert (eds) Gentianaceae: Systematics and Natural History pp. 21–309. Cambridge University Press: Cambridge.
[T-W89] Tenison-Woods, J. E. 1889. On the vegetation of Malaysia. Proceedings of the Linnean Society of New South Wales, series 2, 4 (1): 9–106, pls 1–9.