The saguaro cactus of the Sanoran Desert can grow to be 50 to 60 feet to 18 m) in height and live upwards of 200 years. And when their creamy white flowers begin to bloom in early May and fill the desert landscape, the sight is spectacular.
amorphophallus titanum, commonly called the "corpse flower" due to its odor, which is reminiscent of the smell of a decomposing mammal. it is a flowering plant with the largest unbranched inflorescence in the world and is endemic to western sumatra.
Sea holly (Eryngium alpinum) has a wonderful, steely-blue color, intriguing spiky foliage, and a seriously tough nature. I had to have this in my garden after seeing it in large flowerbeds in Switzerland --- really beautiful!