Buxbaumia viridis leaflet - Plantlife

the copper-coloured Nowellia curvifolia (Fig 4) and Riccardia palmata will movein, provided that the site is humid enough, but other common bryophytes likeLophocolea bidentata, Scapania umbrosa and Cephalozia species may also beabundant.If the log falls onto ground where there is a robust ground flora, large woodlandfloormosses like Hylocomium splendens, Rhytidiadelphus loreus andRhytidiadelphus triquetrus may well overwhelm the log and out-compete thesesmaller species. In such a case the log may be subsumed into the woodlandfloor without ever becoming ‘interesting’.Fig 4. Diversity on logs; left Nowellia curvifolia; right Anastrophyllum hellerianum.Where the log remains relatively free of these large mosses and the normalprocess of decay continues so that the surface is soft and retains moisture anumber of other interesting species may occur. Quite common in the east isAulacomnium androgynum, recognised by its ball of gemmae (small greenpropagules) on a modified stem. In the west, the more common species isTetraphis pellucida, with the gemmae here held in a cup of modified leaves.Less common are the closely related liverworts Tritomaria exsectiformis andTritomaria exsecta, both with red gemmae on the upper leaves; these twospecies can only be separated under the microscope, with the latter speciesmuch the rarer of the two and having a very western distribution.Smaller in scale again is the nationally scarce liverwort Anastrophyllumhellerianum (Fig. 4) which can be locally frequent on logs in Scots pinewoodland. The small size of the plant – only a few millimetres tall and the darkred gemmae on narrow erect shoots mean that the plant is easily recognised buthard to find. Finally, there is the enigmatic liverwort Lophozia longiflora, recordedon just two occasions in the UK, both times from logs near Loch Morlich. It ispossible that the British concept of Lophozia longiflora is too restricted (the plantis very similar to the common Lophozia ventricosa) and that some plants thatwould be accepted as Lophozia longiflora in Scandinavia, are rejected here.