Weed ID - small pointy leaves, reddish stem

[Twilkes]

Any ideas what this is? Grows up to maybe 30cm tall, flowers eventually, hundreds of little ones growing in our garden:



Someone thought it was a form of Impatiens but I can't find any images on the web with any that have as pointy leaves.

[Twilkes]

Mr Pointy said:

It might be Rosebay Willowherb:

https://duckduckgo.com/?q=rosebay+willowherb&t...

If you let it seed you'll have billions of the little blighters.

If it looks like this when small then I don't think so:

http://apps.rhs.org.uk/Advice/ACEImages//RHS_WSYD0...

It starts off tiny and grows upwards more than it grows outwards - this is another baby and medium-sized one, the leaves are quite sparse going up the stem:



Think we skipped weeding one year and now are paying for it.

[Twilkes]

ATG said:

Another vote for one of the willow herbs. That photo showing something broad and close to the ground is about to go off like a jack-in-a-box and become a single stemmed, tall, lanky thing.

Yeah this came up in a search, pretty much what we have: http://c8.alamy.com/comp/E165RD/canalside-weeds-gr... The other types seem much more showy. But yes, just a 'yank it quick' weed, good news.