Eleocharis acicularis

Needle Spike Rush

Needle Spike Rush, Photo courtesy USDA Plants Database

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Eleocharis, from the Greek, `eleios (heleios) , "of the marsh or meadow", and caris (charis) , "joy; grace; kindness; beauty", sometimes a reference to a specific plant.
  • acicularis, from the Latin, acicula, a small pin for a headdress; hence, "needle like"
  • Common Name, from the appearance of the upright stems
  • Other common names include: Hairgrass, Least Spike Rush, Slender Spike Rush, Nåle-Sumpstrå (Dan), Hapsiluikka (Fin), Bioran Dealgach (Gaelic), Nadelbinse (Ger), Vatnsnæli (Is), Naaldwaterbies (NL), Nålesevaks (Nor), Bahnička Ihlovitá (Slovak), Nålsäv (Swe)


  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Liliopsida, the Monocotyledons
      • Subclass Commelinidae
        • Order Cyperales
          • Family Cyperaceae, the Sedges
            • Genus Eleocharis, the Spike Rushes, over 100 difficult-to-distinguish species worldwide.
  • Taxonomic Serial Number: 40025


  • A grass-like, perennial herb with slender stolons, forming large mats of thin flowering stems without leaves on damp shores.
  • Leaves absent
  • Stem erect, thread-like, smooth, somewhat longitudinally ridged, up to 6" long.
  • Roots fibrous, to 10" deep; with fine rhizomes
  • Flowers white, tiny, less than 5mm in diameter, borne in single, sharply pointed, lanceoloid spikelets, up to ¼" long, at the tip of each stem. Flowering June-October.
    • Scales oblong, rounded, or slightly pointed at the tip, up to 1/10" long
    • Sepals absent
    • Petals absent
    • Stamens 3
    • Pistils a 3-cleft style
    • Ovary superior (within blossom)
  • Fruit a shiny, obovoid, achene; straw coloured and up to 1/16" long, with a network pattern on the surface and a cone-shaped tubercle on the top; surrounded by perianth persisting as inconspicuous bristles.


  • A low, grass-like, waterside plant
  • Distinguished from other spikerushes by its diminutive size, thread-like stems and tiny, sharply pointed spikelets.


  • Circumboreal.


  • Edges of ponds, lakes, and marshes; shallow waters
  • Moist soils, wet meadows.


  • Birds: food for waterfowl




  • Sexually by seed
  • Assexually by rhizomes


  • By rhizome division


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Minimum frost-free days - 100
    • Sun full; shade intolerant
    • Soil medium to fine texture, moist, pH 4.5-7.0
  • Size 2"W x 4"-8"H
  • Growth rate moderate



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Last updated on 26 February, 2004