This common riparian moss can form large populations in fast-flowing hill rivers, where it likes flat-topped rocks out in the main flow which are splashed or submerged in times of spate. Its presence usually indicates that the water is base- and nutrient-poor.
Colonies of this moss are typically yellow-brown or yellow-green, hence its specific epithet. Robust, brownish plants can be confused with Hygrohypnum luridum, which has a slightly different ecological niche in more neutral/basic water. That species is also found away from watercourses, for example on shaded stones in paths and damp church gutters.
Unlike H. luridum, H. ochracea very rarely has capsules, so their presence will normally rule this species out. By far the best field character though is its decurrent auricles which have inflated, hyaline cells – with a bit of practice, these can be seen in situ with a good hand-lens.Read the Field Guide account