It has a narrow conical crown with level branches and sometimes pendulous branchlets.
The disk is round, up to 9 mm in diameter, covered by spinelets with a narrow crown of up to 8 points.
'Arnold' - narrow, columnar crown; may flower at early age.
The stems are straight and support few branches generally resulting in narrow crowns.
It is a medium-sized tree, reaching 10-17 m tall, often with a tall, narrow crown; a few species are shrubby.
It is a deciduous shrub or small tree growing to 0.5-8 m tall with one to many stems and a narrow, fastigiate crown.
The growth is fastigiate, with a very narrow crown.
The skin is extremely rough due to a covering of large dermal denticles with narrow, knife-like crowns.
The tree had a straight trunk and a narrow regular, pyramidal crown; the leaves being somewhat smaller than 'Belgica'.
Alstonia macrophylla is a tree with a straight trunk and a high, narrow crown.