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Carex recta – Estuarine Sedge
Species, Flowering plant, Freshwater
Seisg an Inbhir, Hesgen yr Aber, Hesg yr Aber
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Carex remota – Remote Sedge
Species, Flowering plant, Freshwater
Hesg Anghysbell, Hesgen Blodau Anghyfagos, Hesgen Anghyfagos
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Carex riparia – Greater Pond-sedge
Species, Flowering plant, Freshwater
Great Pond-Sedge, Hesgen-y-Dŵr Fawr, Hesgen Braff-Dywysennog
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Carex rostrata – Bottle Sedge
Species, Flowering plant, Freshwater
Hesgen Chwysigennaidd Ylfinfain, Hesgen Ylfinfain, Hesg Gylfinfain
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Carex spicata – Spiked Sedge
Species, Flowering plant, Freshwater
Hesgen Ysbigog Borffor, Hesgen Dywysennog Borffor
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Carex strigosa – Thin-spiked Wood-sedge
Species, Flowering plant, Freshwater
Hesgen-y-Coed Benfain, Hesgen Ysbigog Denau
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Carex vesicaria – Bladder-sedge
Species, Flowering plant, Freshwater
Hesgen Chwysigennaidd Berdywysennog, Hesgen Chwysigennaidd
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Carex viridula – Yellow Sedge
Species, Flowering plant, Freshwater
Yellow-sedge, Hesgen Felen, Hesg Melyn
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Carex vulpina – True Fox-sedge
Species, Flowering plant, Freshwater
True Fox Sedge, Hesgen Dywysennog Fwyaf, Hesgen Dywysennog Fawr
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Carum verticillatum – Whorled Caraway
Species, Flowering plant, Freshwater
Carwy Droellennog, Carwas Troellog
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Catabrosa aquatica – Whorl-grass
Species, Flowering plant, Freshwater
Water Whorl-Grass, Brigwellt Troellennog, Brigwellt Dyfrdrig
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Ceratophyllum demersum – Rigid Hornwort
Species, Flowering plant, Freshwater
Hornwort, Cyrnddail Caled, Cyrnddail, Gwygyrnddail Cyffredin
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Ceratophyllum submersum – Soft Hornwort
Species, Flowering plant, Freshwater, terrestrial
Spineless Hornwort, Cyrnddail Meddal, Cyrnddail Trifforch
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Chamerion angustifolium – Rosebay Willowherb
Species, Flowering plant, Freshwater
Fireweed, seileachain Fhrangach, seileachan Frangach, Helyglys Hardd, Llys y Clochdy, Blodau Santes Fair, Helyglys y Coed, Procer Coch, Tanchwyn, Milwr Coch, Llysiau St Mair, Tanllys
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Chenopodium album – Fat-hen
Species, Flowering plant, Freshwater
Fat Hen, Troed yr Wydd Gwynaidd, Gwydd-Droed Gwynaidd, Troed-yr-Ŵydd Gwyn, Gwydd-Droed Gwyn, Gwydd-Droed Bwytadwy, Tafod yr Oen, Blodau'r Domen, Troed yr Wydd
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Chrysosplenium alternifolium – Alternate-leaved Golden-saxifrage
Species, Flowering plant, Freshwater
Eglyn Bob Yn Ail Ddail, Eglyn Cylchddail, Eglyn Bob Yn Eilddail
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Chrysosplenium oppositifolium – Opposite-leaved Golden-saxifrage
Species, Flowering plant, Freshwater
Eglyn, Eglyn Cyferbynddail, Eglyn Melyn Cyffredin, Tormaen Euraid
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Cicendia filiformis – Yellow Centaury
Species, Flowering plant, Freshwater
Slender Cicendia, Canri Felen Eiddil, Y Ganrhi Felen Eiddil
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Cicuta virosa – Cowbane
Species, Flowering plant, Freshwater
Buladd, Cas-Gan-Fuwch
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Circaea alpina – Alpine Enchanter's-nightshade
Species, Flowering plant, Freshwater
Llysiau-Steffan y Mynydd, Llysiau Steffan Mynyddig