IWoodward's picture

Unknown plant at pond edge

Observed: 2nd February 2013 By: IWoodwardIWoodward’s reputation in PlantsIWoodward’s reputation in PlantsIWoodward’s reputation in PlantsIWoodward’s reputation in Plants
Woodford Golf course poss composite 2012-10-07 4
Woodford Golf course poss composite 2012-10-07 3
Woodford Golf course Bidens achene Oct 2012 (3)
Description:

In mud at edge of pond

Identifications
Species interactions

No interactions present.

Comments

cicuta58's picture

Fruits

I agree this is not B. cernua and could be tripartita var intergra, but these days you need to consider B. connata which has warty achenes as opposed to smooth ones. It is, however, usually by canals.

cicuta58

IWoodward's picture

Thank you both

It seemed too small to be a Bidens (only about 50mm tall). I will try to get back a couple of times over the next few weeks to see if it grows any taller and to check the achenes.

IWoodward's picture

EDIT February 2013

Entry edited 06/02/2013 to add a photo of the achenes (achenes collected late Oct/early Nov 2012 and photographed on 02/02/2013).

Achenes appear to support ID as Bidens tripartita - more or less flat with 2-3 bristles, tapered from apex to base, backward pointing barbs on both the achene and the bristles.