England for a few years, Colquhoun first gained her reputation as a surrealist, and identified as a surrealist for the rest of her life. She used many automatic techniques, which were described in André Breton's first surrealist manifesto as a defining feature of surrealism, and invented several automatic techniques herself. Colquhoun had an early interest in biology, and studies of plants and flowers were a recurring theme in her art throughout her life. Many of her early notebooks contained very detailed drawings of plants, and her early works included a series of enlarged images of flora, occupying the full canvas and painted almost photographically. Colquhoun's work also often explored themes of sex and gender. Her early work often depicts powerful women from myth and Bible stories, such as Judith Showing the Head of Holofernes 1929, and Susanna and the Elders 1930 – both of which are likely homages to Artemisia Gentileschi's works on the same themes. Dawn Ades sees Colquhoun's treatment of gender as responding to the masculine and patriarchal themes in the art of other surrealists – for instance, where other surrealists drew landscapes as women, Colquhoun's Gouffres Amers 1939 shows a male body as a landscape. Several of her works explore themes of castration and male impotence, including Gouffres Amers and The Pine Family, while she portrays female sexuality much more positively, such as in Scylla. Stylistically, some her works have been described as "macabre" and "sinister". In 1939, she created the work Tepid Waters (Rivières Tièdes) which was displayed at her solo exhibition at the Mayor Gallery the same year. The painting, based on a church in Corsica, may allude to the Spanish Civil War. In the 1940s, Colquhoun began to create works exploring the themes of consciousness and the subconscious. Her interest in psychology and dreams also attached her to the Surrealist movement. Colquhoun began to experiment with automatic techniques in 1939, and used a wide range of materials and methods, such as decalcomania, fumage, frottage and collage. Colquhoun went further, developing new techniques such as superautomatism, stillomancy, parsemage, and entopic graphomania, writing about them in her article "The Mantic Stain". Three works which stand out during the 1940s are The Pine Family, which deals with dismemberment and castration, A Visitation which shows a flat heart shape with multicoloured beams of light and Dreaming Leaps, a homage to Sonia Araquistain. Throughout the 1960s and 1970s, Colquhoun