Crassula aquatica

Water Pygmyweed

Water Pygmyweed

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

Name:

• 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)

Taxonomy:

• 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

Description:

• 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

Identification:

• 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.

Distribution:

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

Habitat:

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

Associates:

History:

• Largely overlooked by humanity

Uses:

• None known

Reproduction:

• Reproduces by seed
• Flowers August - September

Propagation:

• By seed

Cultivation:

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

Links:

• Den virtuella floran, from the Naturhistoriska riksmuseet, Stockholm

Comments:

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