Attalea crassispatha has a single stem which grows up to tall. The stem is grey, up to in diameter, and can be columnar, or slightly swollen at the base of the middle of the stem. Individuals bear 15 to 19
pinnately compound leaves—leaves in which rows of leaflets emerge on either side of the axis of the leaf in a feather-like or fern-like pattern—with 127 to 165 pairs of leaflets. Leaves consist of a leaf sheath which wraps around the trunk, a
rachis, from which the leaflets emerge, and a
petiole, which connects the leaf sheath with the rachis. The leaf sheath is open (it does not wrap completely around the stem); when the leaf is shed, the leaf sheath detached cleanly from the stem. The sheath and petiole combined are long, while the rachis is long. The
inflorescences are born among the leaves. They are either predominantly male, or have a mixture of male and female flowers. The inflorescence consists of a main axis—the
peduncle and the
rachis—and a series of smaller branches, the rachillae. The rachillae, which bear the flowers, emerge from the rachis. The peduncle is the main stalk, connecting the rachis with the stem. The
peduncle, the main stalk of the inflorescence, is no more than long and up to in diameter. The rachis is up to while the rachillae, which can number in the hundreds, reach a length of about . The fruit is reddish when ripe. The seeds, which are about long and in diameter are covered by a
mesocarp and a
endocarp. ==Distribution==