Myriophyllum farwellii

Farwell's Milfoil

Farwell's Water Milfoil
Photo courtesy Wisconsin State Herbarium
and Robert W. Freckmann

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

Name:

• Myriophyllum, from the Greek, murios (myrios), "countless, infinite", and fullon (phyllon), "leaf; foliage"; hence "many leaved"
• farwellii, from the Latin, "Farwell's", after American botanist Oliver Atkins Farwell (1867-1944)
• Common name from the Latin, after O.A. Farwell
• Other common names include: Farwell's Water Milfoil

Taxonomy:

• Kingdom Plantae, the Plants
  • Division Magnoliophyta, the Angiosperms (flowering plants)
    • Class Magnoliopsida, the Dicotyledons
    • Subclass Rosidae
      • Order Haloragales
        • Family Haloragaceae, the Water Milfoils
          • Genus Myriophyllum, the Water Milfoils
• Taxonomic Serial Number: 27043

Description:

• A perennial aquatic herb, growing entirely under water
• Leaves ¼"-1¼" long, dissected into threadlike segments, all or most leaves alternate, or more-or- less opposite, or irregularly scattered on stems.
• Stem submerged, sparsely branched, freely rooting at lower nodes.
• Turions present at end of stems.
• Roots white, unbranched, and thread-like; growing from lower nodes. Not always present.
• Flowers single, borne underwater in axils of leaves
• Sepals inconspicuous
• Petals 4, purple; on female flowers only
• Stamens 4, tiny
• Pistil 4-chambered
• Fruit nut-like, 4-lobed with one seed per lobe; 2mm long, each fruit segment with 2 small, bumpy, longitudinal ridges.

Identification:

• A fully submerged aquatic plant, identifiable as a milfoil by its finely dissected, thread-like leaves.
• Distinguished from other milfoils by
  • leaves alternate, rather than in whorls
  • a preference for small bodies of water

Distribution:

• Nova Scotia and Quebec, to New York and Minnesota

Habitat:

• Ponds and small lakes

Associates:

History:

Uses:

Reproduction:

• Sexually by seed (uncommon)
• Assexually by budding (most common)

Propagation:

• Bydivision

Cultivation:

• Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
• Useful as oxygenator in garden ponds, and as shelter for small fishes and aquatic invertebrates.

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