Zostera marina.upload.wikipedia.org (Accessed 4/2014).

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.