Painter. Admired primarily for still lifes, he also painted genre scenes, landscapes, and occasional portraits (including several of his pet squirrel). Decker's life is not well documented, and his career as an artist seems to have followed a bumpy trajectory, as he switched styles and subjects. Success in his lifetime eluded him, and even before his death in a hospital charity ward, his work had been forgotten. Yet, he is admired today for idiosyncratic still life paintings in two different styles. Born in Württemberg, Decker arrived in the United States with his family in 1867. Soon they settled in Brooklyn, where the artist thereafter resided, although he later made several extended visits to his native Germany. As a young man, Decker worked as a housepainter and sign painter while taking evening classes for about three years at the National Academy of Design. In 1879 he enrolled for a year's study at the Munich academy, where he mastered a hard, closely observed realism. The most distinctive of his subsequent still lifes depict unnaturally abundant fruits still attached to tree boughs. Intensely observed individual fruits and leaves disquietingly crowd together in shallow, compressed, and seemingly discontinuous spaces, while compositions seem, as in cropped photographs, to spill beyond the frame. He probably knew the still lifes of William Michael Harnett and fellow Brooklynite William Mason Brown, as well as those of Levi Wells Prentice (1851–1935), who also lived in that borough and painted fruit in a photographically detailed style. However, Decker's works of this time remain singular, perhaps as much indebted to commercial horticultural illustrations as to the accomplishments of his fellow artists. In the 1890s he completely altered his style, adopting a soft, impressionist-influenced brushstroke and a preference for the generalized atmosphere he admired in the work of George Inness. Still lifes remained his most noteworthy contributions, with characteristic examples clustering a few softly glowing fruits on a white tablecloth. They suggest the period's renewed appreciation for still lifes by French eighteenth-century painter Jean-Baptiste-Siméon Chardin. The most original, such as Twelve Plums (Yale University Art Gallery, 1896), also invoke the spare concentration of Chinese or Japanese art, with which Decker is known to have had some familiarity. His poetic landscapes of these years vaporize form in misty atmospheres. Decker ceased exhibiting his work in the 1890s and apparently did not paint for more than a decade before his death.