Crassula aquatica

Water Pygmyweed

Water Pygmyweed
Water Pygmyweed

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


  • Crassula, from the Latin, crassus, "solid, thick, dense, fat, gross", a reference to the succulent leaves of this genus
  • aquatica, from the Latin, aquaticus, "living, growing or found in or by the water; aquatic"
  • Common name from from its tiny size and aquatic habitat.
  • Other common names include: common pigmyweed, Korsarve (Dan), Paunikko, Punapaunikko (Fin), Luibh Beag Bìodach (Gaelic), Wasser-Dickblatt (Ger), Vatnsögn (Is), Firling (Nor), Fyrling (Swe)


  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Magnoliopsida, the Dicotyledons
      • Subclass Rosidae
        • Order Rosales
          • Family Crassulaceae, the Stonecrops/Sedums
            • Genus Crassula, the Pygmyweeds
  • Taxonomic Serial Number: 24099
  • Also known as Bulliarda aquatica, Hydrophila aquatica, Tillaea angustifolia, Tillaea aquatica, Tillaea ascendens, Tillaeastrum aquaticum


  • An annual aquatic herb.
  • Leaves tiny, opposite, linear, succulent, up to ¼" long, spreading, margins entire, petioles absent.
  • Stem branched, ¾"-4" long,
  • Roots
  • Flowers small, 1mm long, single in leaf axils
    • Sepals
    • Petals 4, white or green-white, erect or slightly spreading
    • Stamens 4, alternate with petals
    • Pistils 3-4, with a short style
  • Fruit
  • Seed


  • A small, inconspicuous succulent of shallow waters and muddy shores.
  • Distinguished from other similar species by its very short, succulent leaves growing from a branched stem.


  • Newfoundland and Quebec, south to Maryland, Louisiana, and Texas. Also, Eurasia.
  • Status in Minnesota: Threatened


  • Shallow waters or in wetlands and vernal pools
  • Bare mud flats as water levels recede in the summer, muddy shores.



  • Largely overlooked by humanity


  • None known


  • Reproduces by seed
  • Flowers August - September


  • By seed


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)



  • This is one native species you won't find in most popular field guides.

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Last updated on 26 February, 2004