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I don't understand why it shouldn't be Atocion armeria (= Silene armeria). Palustris's picture really looks like this species which have broad leaves. Palustris's plant is definitely not Silene armena as you can see it on herbarium plate.
The two species names are so similar I bet they get easily confused, it's clear the plant shown is the common Silene armeria. Karaba, I agree the herbarium plate shows a very different species, zooming into the year 1855 collection it is listed as S. dianthifolia, both "armena" and "dianthifolia" in The Plant List are marked as "unresolved", the Plant List also considers the genus Atocian a synonym of Silene.Silene armeria page, lots of good photos.http://luirig.altervista.org/flora/taxa/index1.php?scientific-name=silene+armeriaThis plant (Silene armeria) is also an escaped weed in many parts of the world, here's its non-native extent in North America.https://plants.usda.gov/core/profile?symbol=SIAR
the Plant List also considers the genus Atocion a synonym of Silene.