PbSe nanorods and branched nanorods can be grown using binary Au/Fe3O4 nanoparticles as seeds, as reported by Swihart, Zeng, Prasad, and co-workers on p. 1889. PbSe nucleates on the Au portion of the seed particle and grows anisotropically as one or more straight or branched nanorods. The background images show PbSe nanorods (top), and ternary Fe3O4–Au–PbSe hybrid nanocrystals (bottom). High-resolution TEM images show Fe3O4(purple)–Au(gold)–PbSe (green) ternary nanocrystals. A ball-and-stick cartoon model illustrates the approximate size of these structures relative to the individual atoms.