from P. B. Tomlinson. Palmae. In C. Metcalfe, editor, Anatomy of the monocotyledons, volume 2, page 453, Oxford, 1961. Oxford University Press.
P. B. Tomlinson. Trends in cell dilensions in palms. Amer. Phil. Soc. YRBK, pages 354–355, 1965.
Defined by Tomlinson (1965) who takes into account both end wall slope and the type of perforation plate.
Perforation always scalariform, v. oblique with many thickening bars.
The least specialized:
Chamaedoreae and Iriarteae
Perforation almot always scalariform, v. oblique to oblique with either many or few thickening bars.
Unspecialized:
Areceae, Nypa, Phoeniceae
Perforation plates mixed, including some oblique, scalariform with few thickening bars, other simple and more or less transverse.
Moderatly specialized:
Cocoseae, Caryoteae, Sabaleae, non-scandent Calamoideae, Cryosophileae, Corypheae, Chuniophoeniceae and Trachycapeae
This transitional group include a wide range.
Perforation more or less exclusively simple on transverse end walls.
Most specialized:
Borasseae, climbing Calamoideae