OF THE CAROLINAS & GEORGIA

Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Caryophyllales

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/14/23):
Reynoutria japonica var. japonica   FAMILY Polygonaceae   Go to FSUS key



INCLUDED WITHIN PLANTS NATIONAL DATABASE:
Polygonum cuspidatum   FAMILY Polygonaceae

INCLUDED WITHIN Floristic Synthesis of North America. BONAP (Kartesz, 2021)

Reynoutria japonica

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 5 (2005)

Fallopia japonica var. japonica

INCLUDED WITHIN Floristic Synthesis of North America (Kartesz, 1999)

Polygonum cuspidatum

INCLUDED WITHIN Generic Limits in Polygonum (Ronse Decraene & Akeroyd, 1988)

Fallopia japonica

INCLUDED WITHIN VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 063-04-023:

Polygonum cuspidatum   FAMILY Polygonaceae

INCLUDED WITHIN Manual of the Southeastern Flora (Small, 1933, 1938)

Pleuropterus zuccarinii

 

COMMON NAME:
Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat


         To see larger pictures, click or hover over the thumbnails.

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913    pnd_plzu_001_lvd

        

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm160322_058

March    Greenville County    SC

Riparian zone along urban waterway

Stems erect, stout, striate, papillate, often with red or purple spots, per Flora of China.

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm160322_059

March    Greenville County    SC

Riparian zone along urban waterway

Ocrea oblique, per Flora of China.

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm160331_184

March    Greenville County    SC

Riparian zone along urban waterway

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    s050406_a

April    Greenville County    SC

Roadside

Mid-branch leaves truncate (to very broadly V-shaped), per Weakley's Flora (2012).

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm130628_308

June    Cherokee County    NC

Murphy River Walk

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm0407a_37

July    Greenville County    SC

Mortgage lenders in the UK may refuse to loan on property with Japanese Knotweed.

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm0407b_08

July    Greenville County    SC

Roadside

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm0407b_13

July    Greenville County    SC

Roadside

Flowers in axillary, paniculate racemes. Calyx 1.5-2mm long in flower, per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    s080705_a

July    Swain County    NC

Veins of leaf underside minutely scabrous with scattered bumps, per Weakley's Flora (2012).

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm160818_631

August    Polk County    NC

Pearson's Falls

image of Reynoutria japonica var. japonica, Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat

JK Marlow    jkm160818_632

August    Polk County    NC

Pearson's Falls

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/14/23):
Reynoutria japonica var. japonica   FAMILY Polygonaceae

INCLUDED WITHIN PLANTS NATIONAL DATABASE:
Polygonum cuspidatum   FAMILY Polygonaceae

INCLUDED WITHIN Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Reynoutria japonica

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 5
Fallopia japonica var. japonica

INCLUDED WITHIN Floristic Synthesis of North America (Kartesz, 1999)
Polygonum cuspidatum

INCLUDED WITHIN Generic Limits in Polygonum (Ronse Decraene & Akeroyd, 1988)
Fallopia japonica

INCLUDED WITHIN VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 063-04-023:
Polygonum cuspidatum   FAMILY Polygonaceae

INCLUDED WITHIN Manual of the Southeastern Flora (Small, 1933, 1938)
Pleuropterus zuccarinii

 

Find by SCIENTIFIC NAME:

1122

Forb
Perennial
Monoecious or dioecious

Habitat: Roadsides, disturbed areas, river banks and sandbars, often forming dense thickets, per Weakley's Flora

Non-native: east Asia

Common in Mountains & in NC, rare in GA Coastal Plain, uncommon elsewhere in GA-NC-SC

map
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.


INVASIVE

This plant is causing problems in natural areas outside its native range, according to authorities such as:

 

LEAVES:
Simple
Alternate
Margins entire

FLOWER:
Spring/Summer/Fall
Calyx white (rarely tinged with pink)
5-parted calyx
Petals absent
8 stamens
Superior ovary
Functionally unisexual

Flowers in axillary paniculate racemes

FRUIT:
Summer/Fall
Brown, lustrous
Nutlet

 

TO LEARN MORE about this plant, look it up in a good book!



 


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