In a companion paper in this issue, we have shown that plant collecting in the U.S. is in decline (Prather et al. 2004). We focused on the U.S. only because it was relatively easy for us to measure collecting there, but we are concerned that the decline in collecting may be pervasive worldwide. Because specimens are the fundamental records of biodiversity, we believe that this has serious ramifications in many arenas, particularly in systematic and floristic research, but also in conservation biology, land management, and education, to name only the most obvious. Here we elaborate on the importance of collecting, even in the United States where the flora is relatively well-known. We further discuss some of the many causes of the decline, and encourage the systematics community to advocate continued plant collecting.