Pandanus spiralis is a small tree growing up to tall with a slender trunk, and often with a clumping habit. Prop roots may be present, but are more often absent. The leaves are long and wide, and they may or may not have sharp spines along the leaf margins and midrib. They are arranged spirally on the trunk and branches, and crowded towards their tips. As the leaves die they can form a dense pendant skirt around the trunk below the growing part, and lower down on the trunk the leaf bases often persist, forming a conspicuous spiral. The inflorescences are terminal—on the male plants it is a pendant string of several
spadices each about long, while on the female plants it is a single head about long shrouded by large leafy bracts. The fruit is a
multiple fruit consisting of 10–25 segments measuring long and wide, known as "phalanges". The phalanges are composed of a dense fibrous material with 5–7 seeds embedded in it. The fruit is initially green and turn orange or red when ripe. ==Taxonomy==