Editing Askham Bog (section)

===Herbaceous plants===
[[File:Rubus caesius fruit - Keila.jpg|thumb|European dewberry]]
The diverse flora of Askham Bog is similar to plant communities in southern England.<ref name = "FitterSmith"/> Notable species include [[Ranunculus lingua|greater spearwort]], [[Stellaria palustris|marsh stitchwort]], [[Cladium mariscus|saw sedge]], [[Thelypteris palustris|marsh fern]], [[Rumex hydrolapathum|great water dock]], [[Cirsium dissectum|meadow thistle]], [[Calamagrostis canescens|purple small reed]], ''[[Carex appropinquata]]'' and [[Hottonia palustris|water violet]]. Askham Bog also holds the largest and most north-eastern colony in England of the rare gingerbread sedge ''[[Carex elongata]]'',<ref>David R.&nbsp;W. 1978. The distribution of ''Carex elongata'' in Britain. ''Watsonia'' '''12''': 158–60.</ref> and is renowned for the presence of [[Osmunda regalis|royal fern]].

The vegetation of Askham Bog can be divided into two main groups, reflecting the broad underlying dichotomy between basic and acidic soil. One is a species-rich fen community around the margins. This includes characteristic species such as [[Filipendula ulmaria|meadowsweet]], [[Thalictrum flavum|common meadow rue]], [[Urtica dioica|stinging nettle]], [[Galium palustre|marsh bedstraw]], [[Rubus caesius|dewberry]], [[Solanum dulcamara|bittersweet]], [[Scutellaria galericulata|skullcap]], [[Lysimachia vulgaris|yellow loosestrife]], [[Lysimachia nummularia|creeping Jenny]] and [[Poa trivialis|rough meadow grass]]. The other community is a species-poor acid one towards the centre, including species such as ''[[Sphagnum palustre]]'', [[Molinia caerulea|purple moor grass]], ''[[Rubus fruticosus]]'' and [[Lonicera periclymenum|honeysuckle]].<ref name = "Fitter1980"/> Although the drop in pH and elevational increase on the peat domes is attributable to sphagnum growth,<ref name = "Fitter1980"/> no sphagnum has been found in one vegetation assemblage characterized by honeysuckle and ''Rubus fruticosus'' within the acid centre of the bog.<ref name = "Wilson">Wilson K.&nbsp;A., Fitter A.&nbsp;H. 1984. The role of phosphorus in vegetational differentiation in a small valley mire. Journal of Ecology 72: 463–473.</ref> This appears to be inconsistent with the usual course of succession and may be explained by unusually high concentration of inorganic [[phosphate]].<ref name = "Wilson"/> Low water tables in the raised area may promote mineralization of phosphate, with low pH counteracting microbial conversion to organic phosphate, so that the resultant high inorganic phosphate component in the raised peat favours growth of this plant community.<ref name = "Wilson"/>