Even when not in bloom, silverleaf phacelia packs a visual punch with its bright silvery rosette of leaves. The blooms are fascinating too though - a tall scorpoin-tail shaped inflorescence of small fancy white to purple flowers that uncurls as the blooms mature. As if those attributes weren't enough, this tough species leaves on harsh dry rocky slopes, seemingly unfased by hot rainless summers. 
 
This is an ideal rock garden species, but you can plant it anywhere sunny with well-draining soil. They are short lived but readily resow from seed, so leave old flower spikes intact until the spring. 
 
I've had some really impressively large specimens grow as volunteers in the nursery, and they are always full of a wide range of native bees. Truly one of my favorite plants. Be aware that if they decide to survive in an irrigated setting, they can get a couple feet tall and just as wide. They don't live as long though.