T5 wetlands are dominated by Ramensk's sedge.  They are common in the upper reaches of  estuaries.  T5 corresponds with Vince and Snow's (1984) 'Outer Sedge Marsh Zone 3', estimated to be inundated on only the highest spring tides, or an average of 3 times per summer on the Susitna Flats (with a range of 0-5 times per summer), in upper Cook Inlet, Alaska.  Vince and Snow also found that water was retained for 2-3 days per inundation. 

Pools with common mare's tail (Hippuris vulgairs), Kamchatka spikerush (Eleocharis kamchatica, an Alaska Heritage Program tracked S2S3 rare plant) and saltmarsh starwort (Stellaria humifusa) are frequently encountered within this zone; and between it and the landward Lyngbye's sedge (Carex lyngbyei) zone (T6).  Seaward, a seaside arrowgrass (Triglochin maritima) / goosetongue (Plantago maritima) (T3), or alkalaigrass (Puccinellia spp.) (T4) zone is often encountered.

Ramensk's sedge is a stabilized hybrid between Hoppner's sedge (Carex subspathacea) which purportedly occurs in Western Alaska and further north, and Lyngbye's sedge (FNA ed. comm., 2002).  Sometimes accurate identification is impossible.