“Early Double Tulip: Van de Hoeff,” Alberta, Canada, ca. 1930, hand-colored glass lantern slide by William Copeland McCalla, via Provincial Archives of Alberta Commons on flickr (all images here).
The photographer, William McCalla, was interested in botany and photography from an early age. He studied at Cornell University in the early 1890s and later worked in western Canada as a farmer, librarian, and Natural History teacher. While teaching from 1925 to 1938, he made over 1,000 lantern slides of plants and animals as visual aids.
The slides were donated to the Archives by his son and granddaughter in 1982 and 2007.
You can see more of McCalla’s beautiful flower portraits here.