"Bagnall did not discover the delights of botany until the age of 34, when a friend lent him a microscope." He says of himself that "all my work, whether clerical or botanical, has been done in the scant leisure of a manufactory clerk" and that his "knowledge of botany has been self-acquired." Via the collection of specimens and the collation of records, his main contribution was to what is now called
biogeography. Bagnall was prominent member of the
Birmingham Natural History and Microscopical Society. His herbarium and papers are held by the
Library of Birmingham. The
National Museum Cardiff has 125 of his bryological specimens.
Local Floras Bagnall made important contributions to the
Floras of the counties surrounding his home in Birmingham. One of his earliest publications, in 1874, was a moss Flora of Warwickshire. In 1876, he published a Flora of
Sutton Park, now a National Nature Reserve. There were very few plant records from Sutton Park before this account, so that his Flora served as the foundation for all later Floras. A version with updated species names is available online. This was the first Flora of Warwickshire (
VC38), and was based on a series of papers Bagnall had published in the
Midland Naturalist between 1881 and 1885. The first attempt at a comprehensive Flora of
Staffordshire (
VC39) was by
Robert Garner in 1844. In 1901, when Bagnall was already well known for
The Flora of Warwickshire, his
Flora of Staffordshire was published. This 74 page work was intended to update Garner's Flora and contains a substantial number of new records, many by Bagnall himself. It was only superseded in 1972. Bagnall also contributed the botanical chapter for the 1908 volume of the
Victoria County History of Staffordshire. As with his Flora of Warwickshire, Bagnall divided the county into drainage areas and classified records by these areas.
Bryology Bagnall was a noted field
bryologist. It describes how to study mosses, including the apparatus needed and the preparation and storage of specimens; their development, habitats (including descriptions of typical species) and geographical distribution; and their classification. It also includes chapters on cultivation and use. Bagnall contributed chapters or sections on bryophytes to a number of works, including the
Victoria County History of Worcestershire in 1901, the
Victoria County History of Warwickshire in 1904, the
Victoria County History of Staffordshire in 1908 and
The Botany of Worcestershire in 1909. ==Honours and awards==