A bright green, waxy layer of algae-like plants that sparkles in the sun covering stagnant or slow moving water

  • English Name: Punctate Duckweed
  • Latin Name: Landoltia Punctata
  • Life Cycle: Perennial
  • Dangers: Blocks sunlight from reaching submerged plants, affects boating and recreation
  • States Affected: Is a native weed found across the United States
  • Control Methods: Nets, Rakes, Removal tools, Deskuzzer

The Ways of Wolffia Duckweeds

It is one of the four Duckweeds that dominate North America, alongside the Lemna Duckweed which is the most prevalent, the extra-tiny rootless “Watermeal” Wolffia, and the Giant Duckweed. Like its cousins, the Punctate Duckweeds are incredibly tiny for plants – less than half a cm long – yet grow into massive blankets of green over any suitable water body. They grow in stagnant or very slow-moving water, mostly in dugouts, ponds, marshes, and streams. Because of their tiny size, they tend to look like water pollutants although they are in fact efficient water cleaners. They are one of few weeds that love water with high levels of nitrate and phosphate two common pollutants in industrial, sewage and animal waste.

Separating the Dotted From Other Duckweeds

The signature feature of the dotted duckweed has nothing to do with dots. In fact, the weed has no dots. What it has are ridges on the leaves surface that are really not useful as an identifying mark because the leaves are less than half a cm long. To tell that it is the Punctuate rather than another type of Duckweed, you look at the shape of the leaves. They are narrow, almost egg shaped which is unlike the most common duckweed, the Lamna, whose leaves are almost rounded. Also, and most conspicuous to the naked eye, the dotted duckweed has bright green leaves with a waxy layer that sparkles in the sunlight. No other duckweed sparkles.

To be really sure, you could take a closer look and verify that each plant has two leaves and two to five roots hanging in the water. This is especially useful in differentiating the Punctate from the common Lamne Duckweed, which has just one leaf and one root per plant.

Punctate Duckweed Control

All types of Duckweed are popular with aquatic animals and birds. They are also useful as a source of animal feed and are good water purifiers. But they are also unsightly in the water and often out-compete the animals and birds consuming them. The Puctate Duckweed has the additional problem of being non-native and therefore not as popular with local animals and birds. When it becomes necessary to clear the weed from a body of water, the normal method is physical removal. It is easy because the plant is a rootless floater. An easy way to skim the water and remove this noxious weed is our Deskuzzer Lake Skimmer.

Punctate Duckweed | Lake Bottom Blanket deskuzzer lake skimmer


The Deskuzzer is a 5 foot wide floating seine, that collects surface debris as it is dragged along the surface of the water. It is designed to collect most floating algae, weeds and whatever else is floating on the surface of your lake or pond. When the collection netting is full the Deskuzzer should be emptied on the shore and then redeployed until all the surface debris is gone. The Deskuzzer ships complete with everything one needs – except for the boat, if you choose to use one.

  • Ultra tough screen material for the collection netting.
  • An abrasion resistant guard on lower bar
  • 24 foot long pull line to permit longer throws
  • 5′ Alum. Pole to hold the Deskuzzer when deployed in front of a boat. (add $10.00)
  • Pleated screen edges to help retain the Skuzz.
  • WILL NOT PICK UP WATERMEAL. Please check back with us we are currently working on a solution for watermeal.