One corner of the Dearborn Community Garden (quite extensively documented here yesterday) is set up to evoke a desert. Or maybe just to evoke the scenic/horticultural idea of a desert. It contains succulents and cactuses and white gravel and miniature boulders and a neatly-disposed partial skeleton (or skeleton facsimile) of an unidentified (or completely synthetic) desert creature.
The Badlands in the Mission, with lobelia (lower left corner, immediately above) as an implausible but attractive border plant in electric blue. If San Francisco is anything, it is the host city of fantasy.