# Greater Duckweed (*spirodela polyrhiza*)

Greater Duckweed is a tiny floating plant that loves to grow on the surface of ponds and lakes. It is a great food source for many water animals and helps keep the water clean!

- **Category:** [Plants](https://www.snappit.app/explore/categories/plant)
- **Rarity:** Common
- **Danger:** 0/5 · No known danger
- **Snaps:** 3
- **Habitat:** Freshwater ponds, lakes, and slow-moving streams
- **Also known as:** Duckweed, Lemna, Water Fern

![Greater Duckweed](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Spirodela_polyrrhiza_marais_poitevin.jpg&width=800)

Photo: FAL · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Spirodela_polyrrhiza_marais_poitevin.jpg)

## Appearance

The Greater Duckweed is a small, free-floating aquatic plant that forms bright green mats on the water's surface. Its individual fronds are round to oval, often with a distinctive reddish-purple underside and several fine rootlets hanging into the water, distinguishing it from smaller duckweeds.

## Taxonomy

- **Kingdom:** Plantae
- **Phylum:** Tracheophyta
- **Class:** Liliopsida
- **Order:** Alismatales
- **Family:** Araceae
- **Genus:** Spirodela

## Interesting facts

- Duckweed can produce so much oxygen that it helps other creatures in the pond breathe!
- It's the largest of the duckweed family, yet still often smaller than your pinky fingernail!
- Many fish and birds love to munch on this tiny green plant like it's a super nutritious snack!
- Scientists are studying duckweed to help clean up polluted water and even create new sustainable foods!

## Special abilities

- **Rapid Colonizer:** Greater Duckweed can reproduce incredibly fast, doubling its population in days to quickly cover water surfaces.
- **Water Purifier:** Greater Duckweed can absorb excess nutrients from the water, which helps clean ponds and improve water quality.
- **Winter Survivor:** Greater Duckweed has special buds called turions that sink, allowing it to survive freezing winters underwater.

## Measurements & details

- **Height:** 0.3-1 cm
- **Spread:** 0.3-1 cm
- **Flower Size:** 0.05-0.1 cm
- **Edible:** Yes
- **Toxicity:** None
- **Lifecycle:** Perennial
- **Pollination Method:** Wind

## Ecological connections

- **Eaten by:** Mallard (*Anas platyrhynchos*) — ducks feast on its floating leaves
- **Eaten by:** [Common Carp](https://www.snappit.app/explore/common-carp) (*Cyprinus carpio*) — carp filter-feed on duckweed fronds
- **Eats:** Great Pond Snail (*Lymnaea stagnalis*) — snails graze on its green fronds

## Traits

- [Social](https://www.snappit.app/explore/traits/social): Social animals live in organized groups, cooperating for survival benefits such as foraging, defense, and raising offspring.
- [Filter Feeder](https://www.snappit.app/explore/traits/filter-feeder): Filter feeders obtain nutrients by straining suspended food particles and small organisms from water.
- [Herbivorous](https://www.snappit.app/explore/traits/herbivorous): This trait characterizes organisms whose diet consists entirely or primarily of plant material.
- [Decomposer](https://www.snappit.app/explore/traits/decomposer): Describes organisms that break down dead organic material, recycling nutrients back into the ecosystem.
- [Aquatic](https://www.snappit.app/explore/traits/aquatic): Aquatic habitats encompass environments where organisms live predominantly in water, including oceans, rivers, lakes, and wetlands.

## Collections

- [Plants](https://www.snappit.app/explore/collections/plants)

## Safety

**Danger:** 0/5 · No known danger

No special safety notes yet.

## Frequently Asked Questions

### How to identify Greater Duckweed?

Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details.

### How tall is Greater Duckweed?

0.3-1 cm

### How wide does Greater Duckweed spread?

0.3-1 cm

### How big are the flowers on Greater Duckweed?

0.05-0.1 cm

### Is Greater Duckweed edible?

Yes

### Is Greater Duckweed toxic?

None

### What is Greater Duckweed's lifecycle?

Perennial

### How is Greater Duckweed pollinated?

Wind

## Where to spot

- [Matthaei Botanical Gardens](https://www.snappit.app/guides/places/matthaei-botanical-gardens) — Michigan, US · Botanical Garden
- [Morris Canal](https://www.snappit.app/guides/places/morris-canal) — New Jersey, US · Historic Site
- [Niabi Zoo](https://www.snappit.app/guides/places/niabi-zoo) — Illinois, US · Zoo
- [Upo Wetland](https://www.snappit.app/guides/places/upo-wetland) — KR · Park
- [Crooked Creek Park](https://www.snappit.app/guides/places/crooked-creek-park) — Virginia, US · Park

[View all places to see Greater Duckweed](https://www.snappit.app/guides/where-to-see/greater-duckweed)

## More Plants

- [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*)
- [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*)
- [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*)
- [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*)

---

Source: [Greater Duckweed: Facts & Places to See — Snappit](https://www.snappit.app/explore/greater-duckweed)