Eleocharis acicularis

Needle Spike Rush

Caption

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

Name:

• 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), Bahnièka Ihlovitá (Slovak), Nålsäv (Swe)

Taxonomy:

• 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

Description:

• 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.

Identification:

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

Distribution:

• Circumboreal.

Habitat:

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

Associates:

• Birds: food for waterfowl

History:

Uses:

Reproduction:

• Sexually by seed
• Assexually by rhizomes

Propagation:

• By rhizome division

Cultivation:

• 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

Links:

• Den virtuella floran, from the Naturhistoriska riksmuseet, Stockholm

Comments: