The Centaury genus is very closely related to the Gentians and they look quite similar except that they are pink and gentians are blue.
I have most often seen the Common Centaury growing on Sand dunes, in the more stabilised areas known as Fixed or Grey Dunes. I have also seen it growing along woodland rides and on roadside verges in shady wooded areas albeit in this case in France. I can’t recall ever having seen the Lesser Centaury. It is sort of surprising that a plant that will grow on sand dunes is also found in woodland, although on thinking about it I have seen Stinking Iris, Woody Nightshade and Rosebay Willow herb also growing in both these habitats. There is a species called Seaside Centaury and as you would expect it is found on the coast but it is quite rare and largely restricted to the north western coasts. Also Lesser Centaury has a fairly restricted distribution being largely encountered in the south eastern counties of England. They both seem to like neutral to alkaline soils and a reasonably well drained soil, thus the sand dunes.
The two species differ in that the flowers are more bunched together in the Common Centaury and the seed capsule behind the flower is much longer in the case of the Lesser Centaury. Both species are biennials, producing a little rosette of leaves in the first year and developing a strong tap root which stores food over the winter and then using this energy source in the second year to produce the flower spike and eventually the seeds.
As you can see the depth of the pink colour does vary, I have seen some on sand dunes which are quite a strong pink, then they can become almost white but this seems to me to link to the amount of light they are or are not receiving.