The stem of this curious palm is from twenty to twenty-five feet high and very slender. It is marked with slightly sunk rings and has a few scattered spines. The leaves are rather small, few in number and terminal. The leaflets are rigid, narrowed at the base, widest near the end and suddenly tapering to a point. They are arranged in groups of three or four at short intervals along the midrib, from which they stand out at different angles. The petioles and their sheathing bases are thickly set with slender, flattish, black spines generally pointing downwards.

This species was only found once, growing in the “gapó” or flooded lands of the Upper Rio Negro, and at the time had neither flowers nor fruit. The form and arrangement of the leaflets are so peculiar that it cannot be confounded with any species yet described.

A leaflet is represented of a larger size to show the peculiar form.