Page "Howea" Paragraph 2

The two species can be distinguished by leaf anatomy: H. forsteriana has rather flat fronds with elegantly drooping leaflets, while H. belmoreana has curved leaves with erect leaflets giving the fronds a more angular appearance.

More technically, if the inflorescence is a single spike and the rachis of the leaves is arcuate, the species is H. belmoreana.

If the inflorescence consists of 3 to 5 ( up to a maximum of 8 ) spikes arising from a single broad base, and the rachis of central and lower leaves is horizontal and drooping, the species is H. forsteriana.