She was born in 1904 in London, the only child of Stanley Adshead, an architect and skilled watercolourist who became Professor of Civic Design at Liverpool and then at London University. Her mother took charge of her education and, herself a keen gardener, instilled in Mary an artist's interest in exotic plants and their foliage.
Mary Adshead caught the final years of Henry Tonks's famously misogynist regime when she entered the Slade School in 1921. He took a particular interest in her work and ability, ensuring that she had a flying start when she left by arranging her first mural commission with Rex Whistler as collaborator, for a boys' club at Wapping, in east London.
In her ability to marshal complicated subject matter into witty and elegant designs on a grand scale, Adshead has few peers in the 20th century. Sadly, finished murals are constant prey to design revision of their surrounding and are thus virtually an ephemeral art.
Her next commission, in 1924, for Professor Charles Reilly at Liverpool, is one of the few to have survived - now on display at Liverpool University. A subsequent work - perhaps her best - for Lord Beaverbrook's Newmarket house, is a textbook example of the pitfalls of the art. The brief had been to cover the walls of his dining-room with scenes of Newmarket life such as racing and the fair and to people them with likenesses of his friends. The result was a tour de force of wit and elegance. In the teeming activity Arnold Bennett can be seen playing the harmonium for a crowd of gypsies, Lady Louis Mountbatten waiting by a puncture and Winston Churchill riding on an elephant: they are on their way to meet Beaverbrook at the racecourse.
Lady Diana Cooper, herself pictured picnicking, persuaded him that, given his quarrelsome nature, it was unwise to immortalise a group with whom he was bound to fall out and then find dining with their portraits disagreeable. He found the logic faultless and returned the panels with a two-thirds rejection fee. The panels were reassembled at Peter Jones in 1930 before being rolled up and relegated to a cupboard in the artist's house where years later all but three were destroyed by fire.
Mary Adshead was not a woman to be cast down by disappointment. In 1929 she had married Stephen Bone, son of the artist Sir Muirhead Bone. Both unusually tall, they made a striking and handsome couple. In the early years of their marriage they made tours through Europe, sketching and painting, and in 1930 she had her first solo exhibition at the Goupil Gallery. The commissions for murals, posters and illustrations flowed but the birth of the first of their three children in 1931 inevitably brought distractions. She was an immensely practical woman and a stalwart in the marriage. She taught Stephen to ride a bicycle, running behind him in the park, and once changed a punctured tyre while he sang Irish ballades to the children in the back of the car. She cooked for seven (including her parents), and grew vegetables on a wartime allotment and drew and painted when she could.
She collaborated with Stephen on two illustrated children's books and in 1949 she designed the first pictorial issues of stamps for the GPO. In 1950 she undertook a commission for one of the then largest murals in Britain, decorating the fourth-floor restaurant of Selfridge's store, in London, with jungle scenes. She also organised the Society of Mural Painters.
Mary Adshead was a woman of unusual composure. Her smile and silence were striking, especially when set against her garrulous husband. Her detachment made her an acute observer but did not prevent her from turning a blind eye to what she did not want to see, such as Stephen's dalliances.
His tragic premature death in 1958 in some ways released a new wave of energy in her. She travelled in the United States and Europe, studied mosaic decoration in Ravenna and Sicily and took a course in Italian techniques in mosaic. Unfazed by the all-pervasive disapproval for figurative work, she continued her murals (she completed about 30 during her life) and attracted commissions for house-portraits.
Lameness caused by painting off ladders hampered her work and life in later years, but, ever purposeful, she would crawl where she could not walk with a stick, curious glances notwithstanding.
Her solo exhibition at Sally Hunter Fine Art, in London, in 1986 was a revelation and triumph. Its success left her curiously untouched. At her still centre lay an unwavering confidence in her own ability; if others had taken so long to recognise her talent it was their problem not hers.
Mary Adshead, artist: born London 15 February 1904; married 1929 Stephen Bone (died 1958; two sons, one daughter); died London 3 September 1995.