Zostera marina is a perennial monocotyledon, a submersed aquatic herb, stems to 2.5 m long, freely branched.
Leaves alternate, grass-like, to 1 m long, 3-7 conspicuous, parallel veins, leaves of sterile stems to1 cm wide, those of fertile stems 0.2-0.5 cm wide.
Flowers inconspicuous, enclosed in sheaths 2-8 cm long.
Wetland status: OBL.
Frequency in NYC: Very infrequent if still extant.
Origin: Native.
Habitat: Shallow, quiet salt water of coastal bays.
Notes: Populations have been declining and becoming locally extinct.