Some similarities to : Saxifrages particularly Meadow Saxifrage,
Sandworts. If it were not for the presence of five petals and not four it would also strongly resemble some of the Scurvygrasses.
Not to be semantically confused with : any
Toadflaxes such as Purple Toadflax (Linaria purpurea),
Ivy-leaved Toadflax (Cymbalaria muralis),
Sand Toadflax (Linaria arenaria),
Malling Toadflax (Chaenorhinum origanifolium), Bastard Toadflax (Thesium humifusum)
Flax Dodder (Cuscuta epilinum),
Flaxfield Rye-grass (Lolium remotum), New-Zealand Flax (Phormium tenax),
Toadflax-leaved St John's-wort (Hypericum linariifolium) [plants with similar names belonging to differing families]
No relation to : Fairy Fern [a plant with similar name] nor to Fairy Foxglove (Erinus alpinus) [a plant of very similar name] which is in the Plantain family.
Not to be confused with:
Phlox. Flax and Phlox are quite different flowers, Phlox being a low-growing garden ground-cover plant with five petals similarly coloured.
A very short but ubiquitous plant that colonizes short limestone turf. Its stems are very thin and wiry, with a few branches. The flowers are small, about 5mm across, with 5 white petals, 5 yellow stamens and 5 pale yellow anthers adorn the centre.
Fairy Flax (aka Purging Flax) contains the same toxic cyanogenic glycoside Linamarin as does Cultivated Flax.