Variety tenuis has been distinguished from var. salina by some authors as follows: cyme crowded versus lax, sepals 1.6-3.8 mm versus 2.4-5 mm, mature capsules 3-4.4 mm versus 3.6-6.4 mm, respectively. Due to the extreme overlap in morphologic features as well as geographic ranges, var. tenuis is not recognized here.
The name Spergularia marina var. leiosperma (Kindberg) Gurke has been applied to plants with smooth seeds but, as pointed out by R. P. Rossbach (1940), separation of plants with smooth versus papillose seeds is not practical.
Some authors believe that the correct name for this species is Spergularia marina.