Silverswords (Argyroxiphium)

Silverswords (Argyroxiphium) are rare plants found only in Hawaii. The species in this genus are listed as vulnerable, endangered, and even critically endangered on the IUCN Red List, and one has even gone extinct. These plants resemble large cylinders, with silver leaves sprouting from their bottoms, often growing taller than average people. They bloom only once, sending up a dramatic flower stalk, and then they die shortly afterward, dispersing their dried seed heads.