[2][3] Despite his career in textiles, Sowter's passion for natural history, nurtured from an early age by Arthur Reginald Horwood, sub-curator at Leicester City Museum, shaped his contributions to botany.
This early experience contributed to his later work in compiling data for Horwood and Gainsborough's Flora of Leicestershire and Rutland (1933), for which he collected and listed flowering plants throughout these counties.
In September 1933, during the British Association's visit to Leicester, Sowter led a botanical excursion, demonstrating his growing expertise in the field.
His interest in slime moulds was encouraged by the mycologist Cecil Terence Ingold, who proposed he document the local Myxomycetes.
Sowter's 1960 paper "Our diminishing flora" drew attention to the disappearance of interesting and rare species in the region.
[3] In his younger days, Sowter played tennis for Leicestershire and was also interested in philately, serving as President of the Leicester Philatelic Society in 1937.
[2] Sowter's enthusiasm and willingness to assist others made him a key figure in British lichenology during the first half of the 20th century.