This is a Mason's bone china porcelain Desert Plate in a hand painted pattern called; Central Spray Mixed Border. 
The plate has a "Cabbage Leaf" ware moulded shape. 
This is a beautifully hand painted floral pattern, illustrated on Page 64 of " A Guide to Mason's Patent Ironstone Patterns, published by The Mason's Collectors' Club. This pattern was made in both Ironstone and bone china, as with this piece. The distinctive Cabbage Leaf wares are discussed on Page 160 of the same book which notes that some pieces have the name "Felt Spar" hand written in red script on the base, as with this plate 
A very beautiful early hand painted Mason's Desert Plate
 
Diameter
8.72 in
Height
0.75 in