Painter. Born in Falkirk, Blackadder was educated at Strone Village School, Dunoon Grammar School and Falkirk High School before reading for a degree in fine art at the University of Edinburgh. She then trained at Edinburgh College of Art, where she went on to teach (1962-86). She married fellow art student John Houston (1930 - 2008) in 1956. In 1954, she was awarded a scholarship which allowed her to visit Yugoslavia, Greece and Italy. These travels inspired her early works which were landscapes, including Fifeshire Farm, Roman Wall and Italian Landscape (all 1960 and now in the Tate Gallery), but later she began to produce still life and botanical illustration, both in oil and water colour, for which she is now best known. Her compositions are easily recognisable. They exhibit a Japanese style in terms of space, yet put well known objects in curious association with cats, ribbons, flowers or plants on an empty or abstract background. Blackadder was the first Scottish female painter who was elected to full membership of both the Royal Scottish Academy (1972) and the Royal Academy (1976). Her importance has been recognised by the award of numerous honorary degrees; namely Heriot Watt University (1988), University of Edinburgh (1990), University of Aberdeen (1997), University of Strathclyde (1998), University of Glasgow (2001), University of Stirling (2002) and the University of St. Andrews (2003). She was awarded an OBE in the Queen's Birthday Honours List of 1982 and a DBE in 2003. She was the first woman to be appointed Her Majesty's Painter and Limner in Scotland (2001). Her collections have been displayed at the Tate Gallery (London), the Scottish National Gallery of Modern Art (Edinburgh) and the Museum of Modern Art (New York).