Easily mis-identified as :
Wild Candytuft (Iberis amara) which usually has white flowers but can have mauve flowers (the reverse is true for Garden Candytuft). The fruits of
Wild Candytuft, again flattish, do not have a highly elongated style, but rather a much shorter one that does not extend above the highest point of the fruits. The fruits also lack the triangular points and are much more rounded. The leaves are also lobed rather than the narrow lanceolate of Garden Candytuft.
Can be mistaken for : Perennial Candytuft (Iberis sempervirens) but that is highly branched and grows mainly on walls of gardens, but does escape. It has white flowers and flat fruits that are round with a slight v-shaped notch where the very short style sticks up no higher than the round wings of the fruit. There are a few veins on the inner circle of the fruit absent from those of Garden Candytuft and Wild Candytuft. Also, the leaves are a darker-green that either of the other two Iberis species
Some similarities to : Small Scabious (Scabiosa columbaria) because that too has similar-sized and flat-topped flower-heads with petals which are a similar colour and similarly seem to be larger around the perimeter of the flower. Also, but less so, to Field Scabious (Scabiosa arvensis).
Contact with this plant can result in a rash or contact dermatitis in susceptible individuals. It is a garden plant that can escape into the wild. Flowers can be either mauve, lilac or white.