Allocasuarina torulosa is slender, usually dioecious tree that typically grows to a height of . Its branchlets are drooping, up to  long, the leaves reduced to erect, scale-like teeth  long, arranged in whorls of four or five around the branchlets. The sections of branchlet between the leaf whorls are  long,  wide and more or less square in cross-section when young.
Allocasuarina torulosa is slender, usually single-sex tree that typically grows to a height of . Its branchlets are hanging, up to  long, the leaves reduced to erect, scale-like teeth  long, arranged in clusters of four or five around the branchlets. The sections between the leaf clusters are  long,  wide and more or less square in cross-section when young.