German missionary and plant collector. Born in Solingen, Alfred Lau left Germany to study theology in England and later completed a doctorate in the United States. He spent most of his life as a missionary in Mexico, where he tried to improve the fortunes of young Amerindians through education as well as religion. A keen botanist, he financed his evangelical activities by collecting and selling the seeds of cacti and other succulents. On his collecting trips, which were often made on foot and in the company of his pupils, he discovered many new taxa, including the highly desirable Graptopetalum bellum (Moran & J. Meyrán) D.R. Hunt and Eriosyce laui Lüthy (= Rimacactus laui (Lüthy) Mottram). Besides succulents, he was interested in many other types of plants, especially orchids, carnivorous plants, and passionflowers. The ban by the Mexican government on the export of plant seeds abruptly cut his principal source of funding. His situation was made worse by unsubstantiated rumours about his collecting activities, which were never officially investigated but resulted none the less in his expulsion from the country and followed him to Belize when he settled there. He died from heart disease on 27 February 2007, not long after being authorized to return to Mexico.