This striking plant is an Agave stricta, also sometimes called a hedgehog agave. I photographed it at the University of California Botanical Garden at UC/Berkeley. It was really too bright out that day to photograph broad garden scenes effectively (too much contrast, which makes a garden look harsh rather than inviting), so I moved in close and took advantage of the high-contrast lighting. Such situations also often benefit from thinking and shooting in black and white rather than in color. A tripod and small aperture allowed me to capture ample detail and depth of field.