In the mid-1630s, Athanasius Kircher, the Jesuit inventor, astronomer, medical writer, and would-be translator of Egyptian hieroglyphics, created a device with such powerful implications that fellow scientists and theologians from across Europe, including Pierre Gassendi and Rene Descartes, discussed and debated it. Kircher claimed that, with the aid of a sunflower seed, he had created a perfect clock, one that used a theorized magnetic connection between plants and the sun to run a timepiece more accurate and more perpetual than either the era’s ubiquitous sundials or its increasingly available mechanical timepieces. This clock, as reported by early observers, ran without the benefit of direct sunlight, for instance in a darkened room. And unlike the “rank” and poisonous “midnight weeds” commonly believed to derive their power from the absence of the moon or sun, the sunflower clock promised to demonstrate a consistent solar influence, no less true and life-giving for being invisible. While Kircher could not, subsequently, show that his sunflower seed clock worked as promised, he continued to experiment, substituting a root balanced in water for the original seed during a demonstration in Rome, and later attaching an entire sunflower plant to a rotating disk. This final experiment, described in Kircher’s Magnes siue de arte magnetica (1641), includes a beautiful and detailed engraving of a sunflower in full bloom, growing through a cork disk floating on a pool of water [Figure 3].