curlytop knotweed

(Persicaria lapathifolia)

               
Conservation Status

IUCN Red List

LC - Least Concern

curlytop knotweed

NatureServe

N5 - Secure

SNR - Unranked

Minnesota

not listed

Wetland
Indicator
Status

Great Plains

OBL - Obligate wetland

Midwest

FACW - Facultative wetland

Northcentral & Northeast

FACW - Facultative wetland

Nativity

Native

 
Occurrence

Common

 
Habitat

Wet to moist. Lake shores, pond edges, marshes, wet prairies, ditches, railroads, roadsides, gravel bars, disturbed sites. Full to partial sun.

 
Flowering

July to September

     
Flower Color

Greenish-white to pink

     
Height

24 to 60

     

Identification

This is a 24 to 60 tall, erect, annual forb that rises from a taproot and shallow, fibrous roots.

The stems are ascending to erect, occasionally branched, round, and hairless. They are conspicuously swollen at the leaf nodes.The Latin word polygonum is derived from Greek and means "many knees or joints", referring to the swollen nodes.

The leaves are alternate, variable in shape but usually lance-shaped, 1½ to 4¾ long, and 3 16 to 1½ wide. They are on leaf stalks up to long. The leaf stalks wrap around the stem with a membranous sheath (ocrea) at the base. The ocrea is hairless and does not have a fringe of hairs or bristles on the margin. It turns brown as the leaf matures and eventually peels away. The leaf blades are tapered or wedge-shaped at the base and taper to a point at the tip with concave sides along the tip. The upper surface is hairless. The lower surface is usually hairless, sometimes covered with short, soft, woolly hairs, especially when young. The margins are untoothed. There is sometimes a dark blotch in the middle of the leaf blade, but it is neither as common nor as prominent as with spotted lady’s thumb.

The inflorescence is an unbranched, spike-like cluster (raceme) at the end of the stem and branches and sometimes also rising from the upper leaf axils. The racemes are arching or nodding, robust, dense, 1¼ to 3 long, and 3 16 to ½ wide. They are usually not interrupted. The flowers are arranged in several bundles (fascicles) with 4 to 14 flowers each. The fascicles are sheathed at the base and the sheaths overlap.

Individual flowers are 1 16 to long. There are 5 sepals and no petals (5 tepals). The tepals are fused at the base. The outer 2 or 3 tepals are egg-shaped to elliptic, usually greenish-white, sometimes pink, with prominent, anchor-shaped veins. There are 5 or 6 stamens and 2 or 3 styles. The stamens have pink or red anthers. The styles are fused at the base. The flowers rarely open, so the stamens, styles, and inner tepals are difficult to see. There is no fragrance.

The fruit is dark brown to black, oval, 1 16 to wide achene. The achene is flattened or concave on both sides.

 
Similar
Species

Pennsylvania smartweed (Persicaria pensylvanica) racemes are mostly held erect, rarely nodding. The flowers are often pink.

Spotted lady’s thumb (Persicaria maculosa) is a smaller plant, no more than 32 in height. The ocrea has a few short hairs on the margin. There is usually a prominent, dark blotch in the middle of the leaf blade. The flowers are pink to rose.


Distribution Distribution Map   Sources: 2, 3, 4, 5, 7, 22, 24, 28, 29.

Comments

 


Taxonomy

Family:

Polygonaceae (buckwheat)

 

Subfamily:

Polygonoideae

 

Tribe:

Persicarieae

 
Synonyms

Persicaria incarnata

Persicaria tomentosa

Polygonum incanum

Polygonum incarnatum

Polygonum lapathifolium

Polygonum lapathifolium var. incanum

Polygonum lapathifolium var. nodosum

Polygonum lapathifolium var. ovatum

 

Polygonum lapathifolium ssp. pallidum

Polygonum lapathifolium var. prostratum

Polygonum lapathifolium var. salicifolium

Polygonum nodosum

Polygonum oneillii

Polygonum pensylvanicum ssp. oneillii

Polygonum scabrum

Polygonum tomentosum

 
Common
Names

curltop ladysthumb

curlytop knotweed

curlytop smartweed

dock-leaf smartweed

dock-leaved smartweed

heart’s-ease

 

nodding smartweed

pale persicaria

pale smartweed

smartweed

willow weed


 

 

 

 

 

 

 

 

 

Glossary

achene

A dry, one-chambered, single-seeded fruit, formed from a single carpel, with the seed attached to the membranous outer layer (wall) only by the seed stalk; the wall, formed entirely from the wall of the superior ovary, does not split open at maturity, but relies on decay or predation to release the contents.

 

axil

The upper angle where a branch, stem, leaf stalk, or vein diverges.

 

fascicle

A small bundle or cluster, often sheathed at the base, as with pine needles.

 

node

The small swelling of the stem from which one or more leaves, branches, or buds originate.

 

ocrea

A sheath around the stem at the base of a petiole formed from the stipules; a feature of many members of the Polygonaceae.

 

petiole

The stalk of a leaf blade or compound leaf that attaches the leaf blade to the stem.

 

raceme

An unbranched, elongated inflorescence with stalked flowers. The flowers mature from the bottom up.

 

sepal

An outer floral leaf, usually green but sometimes colored, at the base of a flower.

 

sheath

The lower part of the leaf that surrounds the stem.

 

stipule

A small, leaf-like, scale-like, glandular, or rarely spiny appendage found at the base of a leaf stalk, usually occurring in pairs and usually dropping soon.

 

tepal

Refers to both the petals and the sepals of a flower when they are similar in appearance and difficult to tell apart. Tepals are common in lilies and tulips.

       

Visitor Photos

   
Share your photo of this plant.

Bill Reynolds


  curlytop knotweed    

       
       
       

MinnesotaSeasons.com Photos

   

Plant

  curlytop knotweed   curlytop knotweed
       
  curlytop knotweed    
       

Inflorescence

  curlytop knotweed   curlytop knotweed
       

Leaves

  curlytop knotweed    
       

Compare Pennsylvania smartweed on the left with curlytop knotweed on the right

  Pennsylvania smartweed    
       
       

 

Camera

     

Slideshows

   
  Pale Smartweed (Polygonum lapathifolium)
Bill Keim
 
  Pale Smartweed (Polygonum lapathifolium)  
     
  Persicaria lapathifolia (Nodding Smartweed)
Allen Chartier
 
  Persicaria lapathifolia (Nodding Smartweed) (  

 

slideshow

     

Visitor Videos

   
Share your video of this plant.

     
     

Other Videos

 
  Pale Persicaria (Persicaria Lapathifolia L.) - 2012-09-02
W3stlander
 
   
 
About

Published on Sep 5, 2012

Pale Persicaria (Persicaria lapathifolia (L.) Delarbre, syn. Polygonum lapathifolium L.) is a plant of the family Polygonaceae. It is closely related to Redshank and as such is considered a weed in Britain and Europe.

Other common names for the plant include pale smartweed, curlytop knotweed, and willow weed.

-----------------
De beklierde duizendknoop (Persicaria lapathifolia, basioniem: Polygonum lapathifolium), knopige duizendknoop of Bleek knoopkruid is een algemeen voorkomende, eenjarige plant uit de duizendknoopfamilie (Polygonaceae).

 
     
  European Honeybee on Persicaria セイヨウミツバチ♀がオオイヌタデを訪花採餌
sigma1920HD
 
   
 
About

Published on Dec 26, 2014

Foraging workers of European honey bee (Apis mellifera, family Apidae) visiting pink flowers of (Persicaria lapathifolia, family Polygonaceae) for nectar and pollen. Mid-September 2014 in Japan.

日本語による詳細はブログをご覧下さい。
http://sigma-nature-vlog.blogspot.jp/2014/12/blog-post_44.html
オオイヌタデの花で採餌するセイヨウミツバチ♀

 
     
  Curlytop Knotweed, オオイヌタデ
Koji Kimura
 
   
 
About

Published on Sep 7, 2013

Curlytop Knotweed, オオイヌタデ

 
     

 

Camcorder

         

Visitor Sightings

   
Share your sighting of this plant.

Bill Reynolds
7/27/2015

Location: Pennington County

 

curlytop knotweed


     
     
 

MinnesotaSeasons.com Sightings

   


 

 

Binoculars

Last Updated:

About Us | Privacy Policy | Contact Us | © 2017 MinnesotaSeasons.com. All rights reserved.