Galls and Rusts List 

AMPHIBIOUS BISTORT

Persicaria amphibia

Dock & Knotweed Family [Polygonaceae]  

month8jul month8july month8Aug month8sep month8sept

status
statusZnative
 
flower
flower8pink
 
morph
morph8actino
 
petals
petalsZ5
 
type
typeZclustered
 
type
typeZspiked
 
stem
stem8round
 
sex
sexZsterile
amphibious

AMPHIBIOUS FORM

12th Aug 2005, Maghull, Leeds & Liverpool Canal. Photo: © RWD
The amphibious form has floating leaves that differ from the terrestrial form in being heart-shaped near the base.


14th July 2007, Bridgewater Canal, Salford, Greater Manchester. Photo: © RWD
The flowers are held about 2 - 4 inches above the level of the water.


30th June 2016, a small pond, freshfield, Sefton Coast. Photo: © RWD
The florets here the mostly old and bedraggled petals have fallen off revealing some anthers and a style or two.


12th Aug 2005, Maghull, Leeds & Liverpool Canal. Photo: © RWD
Five pink rounded petals with protruding white stamens bearing pink anthers on them.


22nd June 2007, Waters Meet, Bridgewater Canal, Eccles, Greater Manchester Photo: © RWD
Unlike the terrestrial form the leaves are hairless and have a slightly heart-shaped base.


30th June 2016, a small pond, freshfield, Sefton Coast. Photo: © RWD
This is a specimen which has probably only recently discovered that it is now standing in water - a very small pond. It's leaves are not floating on water, but are instead up in the air about something. Here are the minute forwardly-directed teeth on the leaf edge, possibly the tiniest leaf teeth your Author has never noticed before - the leaf stalk is off-screen to the right.




TERRESTRIAL FORM

Much less frequent than the Amphibious form

19th Aug 2017, Crosby Dunes, Sefton Coast Photo: © RWD
On sand dunes near the west coast. Sandy Shore is just over those hillocks where there's always something there to remind me :-)


19th Aug 2017, Crosby Dunes, Sefton Coast Photo: © RWD
The sand lets any rain easily percolate through, keeping it relatively dry, certainly free of standing water.


19th Aug 2017, Crosby Dunes, Sefton Coast Photo: © RWD


19th Aug 2017, Crosby Dunes, Sefton Coast Photo: © RWD


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
On land it grows up to 60cm tall. It totally lacks the dark chevrons on the leaves typical of Redleg.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
Bird's-eye view. The terrestrial form differs from the amphibious form in that the leaves are smaller and they are oblong-lanceolate and not oblong heart-shaped with rounded auricles at the base and are slightly hairy. The terrestrial form is also often barren without flowers.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
The flowers are much the same as those of the amphibious form.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
As-yet unopened flowers at the bottom, some open ones in the middle with slightly protruding white stamens bearing pink anthers.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
Each floret has a brown papery sheath around the base.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
Unlike the otherwise fairly similar Redshank (those lacking the not-always-present dark chevron on the leaves), the sheaths are not frilly.


20th Aug 2014, waste ground, Hightown, Sefton Coast Photo: © RWD
Un-like the amphibious form the leaves may be slightly hairy.




A GALL
Wachtiella persicaria
on the Terrestrial Form

 Galls and Rusts Menu

9th Aug 2014, waste ground, Hightown, Sefton Coast. Photo: © RWD
A gall formed on Bistort leaves (this specimen infecting the top three leaves on the Terrestrial form of Amphibious Bistort, but it can infest Common Bistort) by the gall mite Wachtliella Persicariae which causes a severe distortion of the leaves. It can cause just the rolling up and thickening of leaf margins or the whole leaf to roll up completely and redden. If there is one plant infected, the likelihood is that several others nearby will be similarly affected, as was the case here.


5th July 2014, Rimrose Valley Country Pk, Sefton. Photo: © RWD
Unlike other leaf galls that cause the rolling up of leaf margins, this gall makes the leaves so brittle that they cannot be un-rolled without breaking them. It is found throughout summer with each gall containing several light-red or orange larvae which pupate later in the year.


The same plant can exist in two slightly different forms, the amphibious form either on wet grass near water, or actually in the water; or the terrestrial form which is well away from water on waste ground.

It occurs in water or wet places, riverbanks and as a weed on rough ground throughout of the British Isles.


  Persicaria amphibia  ⇐ Global Aspect ⇒ Polygonaceae  

Distribution
family8dock family8knotweed family8Polygonaceae
 BSBI maps
genus8persicaria
Persicaria
(Bistorts)

AMPHIBIOUS BISTORT

Persicaria amphibia

Dock & Knotweed Family [Polygonaceae]  

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