Born in Country Harbour, Nova Scotia, Maria Morris grew up in Halifax after the death of her father, Guy Morris, in 1813. Her mother opened a school in the city where Morris would eventually head the School of Drawing and Painting. She trained under W. H. Jones between 1828 and 1830 and continued her studies in 1832 under the visiting English painter L'Estrange who advertised his particular "style of flower painting" in that year. She rapidly established herself as an artist of note in the company of William Eagar, William Valentine, and John S. Clow.
In 1836, she was toasted as "Painter of the Year" by the North British Society of Halifax. By this time, she had aligned herself with Titus Smith, the first Secretary of Agriculture for Nova Scotia, to produce watercolour paintings of the native flora of the province. With Smith as her scientific mentor and her aesthetic judgement to guide her artistically, Morris began to produce albums of her watercolour drawings of Nova Scotian wildflowers in the mid 1830s. Many of these drawings, along with several other of her paintings, would be included in the big 1848 art exhibition in the city.
With the support of Smith, who provided a brief scientific description of each plant, and the patronage of the governor, Sir Colin Campbell, Morris arranged for a London bookseller to publish six of these botanical illustrations as lithographs in 1840. She issued a second series of lithographs through her London publisher in 1853. Alexander Forrester, who lectured on botany at the Mechanics' Institute, provided the scientific notations for these illustrations. A third set of lithographs was published in 1866, this time with notations by George Lawson, the Edinburgh-trained botanist who had founded the Botanical Society of Canada. Lawson also assisted the reissue, on new lithographic stones, of the 1840 series the following year.
The production of these four sets of lithographs, documenting twenty-two native plants, straddles the period between the "intellectual awakening"and Confederation in Nova Scotia, a period marked by patriotic fervour and utopian dreams. Maria Morris's effort to record the diverse flora of her native land is in accord with the patriotism of the era; her scientific and artistic attempt, with the utopian pursuit. She married Garrett Miller in 1840 and died in Halifax in 1875.