"I have shown," wrote the Swedish artist Hilma af Klint, "that there is a connection between the plant world and the world of the soul." Her Nature Studies portfolio (1919-20), recently acquired by The Museum of Modern Art, New York, comprises 46 sheets of exquisitely rendered botanical drawings. Documenting each plant's particular qualities along with Latin names, Swedish common names, and dates of observation, af Klint follows the typical format of a botanical reference book, known as a Flora; however, hers is a Flora of the spirit, a mapping of the natural world in spiritual terms that would stand alongside any scientific resource. Carefully drawn and vividly colored plants, flowers, and lichen are juxtaposed with geometric forms: a blooming sunflower is echoed by three nested circles, a central dot, a solid red line, a ring of points; a white narcissus is set against a pinwheel of softened primary hues; a cluster of budding branches is accompanied by checkerboard boxes of dots andstroke.