M. myosotis occurs typically at the base of halophyte, vascular plants on saltings and Puccinellia maritima sward by tidal rivers, frequently congrugating under driftwood.
M. denticulata occurs typically under stones at EHWS on shores without vascular plants.
At sites with a combination of halophyte vascular plants and stone, the two species/forms may be found together at EHWS, regardless of salinity, which is often stated to be a governing factor for occurrence of one or the other species (e.g. Forbes & Hanley, 1853). At the low salinity riverside site above, a cliff adjoins Puccinellia maritima sward. Under stones at the juncture of cliff and sward there were many M. myosotis and a few M. denticulata. The latter is incorrectly supposed to require full marine salinity.
Left: X marks position on P. maritima sward at base of cliff.
Centre: X = turned up stone. PVC glove for scale.
Right: X = soil under stone.

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