ExplorePlants

Japanese knotweed

Reynoutria japonica

Japanese knotweed is a tall plant with big green leaves and white flowers. It grows quickly and can be found in many places, often near water. It's important to know about it because it can take over other plants!

Habitat: Urban areas

Appearance

The Japanese knotweed has sturdy, hollow stems that are often reddish-purple, resembling bamboo. Its leaves are heart-shaped or spade-like, bright green, and grow alternately along the stem, making it distinct from many native plants. Small, creamy-white flowers appear in clusters.

KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderCaryophyllalesFamilyPolygonaceaeGenusReynoutria
Japanese knotweed
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Japanese knotweed

Category

Plants

Rarity

Common

Danger

2/5 · Low

Snaps

Be the first to snap!

Interesting facts

Its roots can break through concrete and asphalt!

Some call it the "Hulk Plant" because it's so tough to get rid of!

This plant can grow a whole foot taller in just one summer day!

Young knotweed shoots are eaten like rhubarb in Japan for tasty treats!

Special abilities

Ability

Root Power!

Japanese knotweed can grow incredibly deep and strong roots that help it break through concrete and even house foundations!

Ability

Super Regenerator!

Japanese knotweed can regrow from tiny stem or root fragments, helping it quickly spread and survive almost any damage.

Ability

Shade Conqueror!

Japanese knotweed grows so fast and dense that it shades out other plants, helping it dominate new areas quickly.

Measurements & details

Height
200-400 cm
Spread
100-500 cm
Flower Size
0.1-0.3 cm
Bloom Season
Late_summer_early_fall
Edible
Yes
Toxicity
Mild
Lifecycle
Perennial
Pollination Method
Insect

Ecological connections

pollinates

European honey bee

Apis mellifera

Visits its white summer flowers.

eats

knotweed leaf beetle

Gallerucida bifasciata

Beetle larvae munch its leaves (native).

shelters

house sparrow

Passer domesticus

Small birds hide in dense thickets.

Traits

Also known as

No aliases listed yet.

Collections

Safety

Danger

2/5 · Low

Do not touch or eat any part of the plant without asking an adult first.

Frequently Asked Questions

How tall is Japanese knotweed?

200-400 cm

How wide does Japanese knotweed spread?

100-500 cm

How big are the flowers on Japanese knotweed?

0.1-0.3 cm

When does Japanese knotweed bloom?

Late_summer_early_fall

Is Japanese knotweed edible?

Yes

Is Japanese knotweed toxic?

Mild

What is Japanese knotweed's lifecycle?

Perennial

How is Japanese knotweed pollinated?

Insect

Snap Map

Zoom in to split clusters and explore where this object has been snapped.

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Recent Snaps

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Where to spot

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