He obtained his PhD in 1925 at the Jagiellonian University in Kraków for his studies on the ecology of saxicolous lichens (growing on or living among rocks) in Europe.
Afterwards, he spent several years researching the large lichen genus Usnea, culminating in the publication of a two-volume monograph during 1936–1938.
A year later Motyka was appointed as Director of the Plant Geography and Systematics department at the Maria Curie-Skłodowska University in Lublin, and soon after became an associate professor.
Motyka's draft manuscripts on the lecanoroid lichens were published posthumously in 1995–1996 by his daughter Maria Motyka-Zgłobicka and J. Sieminska, in a four-volume work titled Lecanoraceae.
However, there were several problems in Motyka's text, such as the use of outdated generic concepts, little discussion of why taxonomic decisions were made, and omissions of important information for many of the newly described species.