Habit: Cyperus polystachyos grows as a clumping annual/perennial herb to 70 cm in height when in flower, with a triangular stem. The basal leaves to 50 cm in length and 5 mm wide with an acute/acuminate leaf apex and scabrous margin. The leaf sheath yellow – brown.
The incomplete, perfect flowers are arranged in a cluster of 5 – 30 linear spikelets in a congested panicle. The spikelets are at the end of a triangular shaped peduncle and are subtended by 3 – 7 leaf like bracts to 25 cm in length. The spikelets are brown at maturity, to 3 cm in length. Each spikelet has 20-30 flowers with a zig-zag rachis. The flowers are subtended by an ovate brown bract. There is no calyx or corolla. There are 2 – 3 stamens. The ovary is superior with a single locule with a 2-parted style. The fruit is a oblong achene at maturity.
Habitat: Cyperus polystachyos grows in wet Human Altered environments (old fields and roadsides).
Distribution: Cyperus polystachyos occurs in the northern island groupings of the Lucayan Archipelago as well as the Caribbean region and globally in tropical and subtropical regions
Medicinal/Cultural/Economic usage: Cyperus polystachyos is not known to be used medicinally in the Lucayan Archipelago.