“Pinks” in this case refers to plants in the pinks family, Caryophyllaceae, so named not for the color but for the jagged edges on the petals (in some species), which look as though they’ve been cut with pinking shears.
The Caryophyllaceae is a cosmopolitan family, and a big one, with over 2,000 species in 80 genera. The genus Silene is said to be the largest genus in the family; on-line sources list anywhere from 300 to 700 species in it.
There are five species of Silene in Iceland, though you may only find three in many sources; the two others are Lychnis species that have recently been renamed. There are about a dozen in Maryland, of which only four are native.
moss campion; cushion pink
This plant grows almost everywhere in Iceland except on the glaciers. It’s similar in form to our native S. caroliniana ssp. pensylvanica (wild pink):
The flowers of the Icelandic species are smaller, and although the plant itself can be sprawling, overall the leaves and blossoms are quite compact. Wild pink is more open, and doesn’t grow as large.
Native to subarctic Fennoscandia, red campion can be found as an introduced species in both Iceland and North America (Canada and about half of the US). In Iceland it occurs in only a few lowland areas; I found it near Akureyri and Ólafsfjörður.
formerly Lychnis alpina,
alpine catchfly, alpine campion
Not quite as common as S. acaulis, but still pretty widespread. Its native range includes northeastern Canada, Greenland, and Fennoscandia. I found both the white and pink forms near Húsafell.
formerly Silene maritima ssp. islandica
Although widely available in the nursery trade in the US, S. uniflora is endemic to Iceland. It’s easy to identify because there’s nothing quite like it. It’s common in the central highlands as well as much of the lowlands. I saw it near Ísafjorður, Akureyri, and Húsafell.
Just for fun, here’s the other Silene I’ve found in the Maryland Piedmont: S. stellata (starry campion), which should be blooming now. Maybe I’ll go hunting for it and try to get better pictures.