I have found D. linearis growing in interdunal swales along the coast of
northern Michigan. Every location I found for D. linearis also had
D. rotundifolia, usually in a slightly different microhabitat. The
D. linearis tended to grow in wet substrate or was partly submerged, while
D. roundifolia grew on slightly higher mounds of plant material and/or at
the edges of the "bog". In one site I found a couple plants of intermediate
morphology, presumably hybrids between these two (no other Drosera species
were found nearby).
Michael Chamberland