Scentless Mayweed - Tripleurospermum inodorum

Erect, branched low to medium plant with feathery leaves. Flowerheads are white with a yellow disc, not aromatic, the white rays not reflexing fully after opening, and the disc cone not hollow.

Scented Mayweed (Matricaria chamomilla) and Chamomiles (Anthemis and Chamaemelum nobile)

There is a very common and similar white daisy of waste ground and arable margins - Scented Mayweed (Matricaria recutita (synonym = M. chamomilla).  Both species can be aromatic.  The best way to tell is to slice through the boss of yellow florets (the receptacle) in the centre of the flower with your thumbnail; Scented Mayweed has a definitely hollow receptacle and Scentless Mayweed has a more or less solid receptacle. 

Chamomile (Chamaemelum nobile), Corn Chamomile (Anthemis arvensis), Stinking Chamomile (Anthemis cotula) and Austrian Chamomile (Cota austriaca (synonym = Anthemis)) have all been recorded in VC55, but are scarce or very rare; a specimen will be needed to verify them.  They all have scales among the yellow florets on the receptacle, unlike Matricaria or Tripleurospermum.  Corn or Austrian Chamomile are often included in seed-mixes of cornfield annuals, and are occasionally naturalised.

A photograph of the whole plant, with detail of sliced-through receptacle

Cultivated and arable land, waste ground.

July to September.

Annual.

Common throughout much of Britain, but scarcer in the north.

Very common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 600 of the 617 tetrads.