Eleocharis acicularis is a perennial C3 spikerush (Pascal-Antoine 2008), tufted, very small, slender, colonial from rhizomes and stolons, forming carpets, stems filament-like, about 3-12 cm tall, angular, furrowed.
Leaves bladeless, sheaths only.
Flower spike terminal, about 0.5 cm, flattened 3-15 flowers, scales 0.2 cm, midrib papery with greenish, often reddish along margins.
Fruit a dry achene, pale, 0.1 cm, 3-sided, tipped with hat-shaped tubercle, July-Sept.
Wetland status: OBL.
Frequency in NYC: Very infrequent.
Habitat: Wet, open soil, shores.