Persicaria maculosa is accepted on the Plant List ..
http://www.theplantlist.org/tp...
So is Persicaria lapathifolia..
http://www.theplantlist.org/tp...
How to separate the two?
http://de.wikipedia.org/wiki/D...
The next link calls P. maculosa 'Redshank', look at the leaf photo, they look shorter and broader.
http://www.aphotoflora.com/d_p...
The leaves look to vary, the stems in general look to be very red but not always.
http://www.wnmu.edu/academic/n...
http://keyserver.lucidcentral....
Both seem to be variable, altough P.maculosa appears to have pink or red flowers where Persicaria lapathifolia ' Pale Persicaria' are generally pale (how many photos are correct anyway, unless there's regional variation.) The brown blotch on maculosa looks to be further towards the leaf tip.
Persicaria maculosa ..
This is a very common weed which is found in wet places, fields, waste ground and even growing out of the crack between pavement and wall. A late summer flowerer it is usually the pink colour in the left but the unusual red form shwon was in every other respect a normal P. maculosa.
http://www.ukwildflowers.com/W...
Persicaria lapathifolia ..
The diagnostic for this plant is the presence of small glands on the flower stem and on the perianth (sepals) but I first look out for a pale greenish flowered Persicaria often growing with P. maculosa (Redshank) and P. hydropiper (Water Pepper). In my experience a healthy plant will often be larger and more straggly than Persicaria maculosa which can have confusing pale forms. I haven't yet seen any pink forms of P. lapathifolia as illustrated in Stace's DVD.
http://www.ukwildflowers.com/W...
http://www.naturespot.org.uk/s...
The leaf venation appears to be closer on Persicaria lapathifolia too, yours looks to be close. Persicaria maculosa "generally" has a more lax habit.
http://www.invasive.org/browse...
