Whiteadder Water

Site of Special Scientific Interest · 55.7932, -2.2273

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Also within

Berwickshire County

Condition (NatureScot)

Unfavourable No Change (1)
UnitFeatureConditionArea (ha)Assessed
F1 Palaeozoic Palaeobotany Unfavourable No Change — 2013-05-06

Habitats

Fast flowing river and stream

Geology & landscape

Geological Period: Carboniferous

Description

Whiteadder Water The Whiteadder Water Site of Special Scientific Interest (SSSI) is located between Preston and Foulden in Berwickshire, north-west of Duns. The site comprises a section through the Lower Carboniferous Cementstone Group and is one of the most important palaeobotanical areas in Britain. Cementstones exposed in the river bed scaurs yield a flora of unprecedented diversity for its age in an exceptional state of preservation; in most specimens, cell structures can be readily observed. There are over 40 species of ferns, progymnosperms (believed to be ancestors to the conifers), pteridosperms (seed-bearing ferns) and lycopods (ancestors of club mosses), many of which are unique to the section. The assemblage throws an important light on the earliest Carboniferous floras, which were the starting point for the rapid diversification in terrestrial vegetation that characterised the rest of the period. Particularly important are the seeds, which are the oldest known examples with anatomical details preserved, and thus vital for understanding the early evolution of this organ. All in all, this section is a palaeontological site of wide international significance.

Plant communities

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea