1) Dicot genus 2) Genus alstonia 3) Magnoliopsid genus 
Alstonia is a widespread genus of evergreen trees and shrubs, of the dogbane plant 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. Alstonia consist...
[n] - genus of evergreen trees or shrubs with white funnel-shaped flowers and milky sap
genus Alstonia noun genus of evergreen trees or shrubs with white funnel-shaped flowers and milky sap; tropical Africa to southeastern Asia and Polynesia