Persicaria stagnina

Persicaria for id RV1 : 11 posts by 5 authors. Attachments (7).
Please id this Persicaria sp. from a river bed in Thane district.
Pictures taken on 29th December 2013 and today. (22.2.14)
Flowers white, slightly pink, stamens 5 - 7, leaves mostly green and a few with purple blotches, pubescent and slightly pale beneath, stems hairy, nuts black. the racemes are fairly short and slender. Whole plant about 2ft in height.

I think Persicaria barbata (L.) Hara
please check for P. hydropiper.
Thank you ... for your replies.
I find these quite difficult to identify.
It seems to me that P. barbata var stagnina is a possibility: stems strigose hairy, leaves pubescent- hispid, peranth white or tinged with pink. It might not be var. barbata because the stems of my plant are not stout.
In Hooker there is a description of Polygonum stagninum where he mentions stamens are 5 to 7.
Thanks for your comments ... I guess the leaves are strigosely hairy below in the posted plant (as seen in P 1200395.JPG). But, if we follow the key provided in Fl. Pakistan, cilia should be much shorter than the tube. Still I'll go with your identification as the strigose character seems more reliable to me. Further, as per the updated nomenclature, the plant should be treated as a distinct species i.e Persicaria stagnina (Buch.-Ham. ex Miz.) Qaiser. But please check your plant/specimen one more time for the above mentioned characters.
I appreciate your detailed reply.
Here are 2 more pictures:  the underside of a leaf, and a close up of the stem. 
Thanks for the clear photographs ...! I appreciate your photography skills!! Further I would say the characters are pointing towards P. stagnina. Experts may add their view.
Thanks ... for sharing this plant.
I would have not given a second thought for querying the ID, and would have taken for granted the plant as Persicaria glabra.
Thanks to ... for the discussion, and getting nearer to the ID.
Thanks to you all for comments and especially to Ritesh ji for looking into this plant in such detail.
For now I'll keep it as Persicaria stagnina