Early Marsh Orchid pulchella
The "Diploid" Marsh orchid family is generally split into four subspecies in the UK. In Dorset we have two, both have pale, broad and unspotted leaves. pulchella has a darker red flower and is the variety that can be found with sphagnum moss in acid bog.
The area West of Warham supports this plant; this picture is from Worgret Heath.