Other cycads grow in loose stands in grasslands, forming a kind of savanna. Exceptional among the cycads are species of Encephalartos , one of which is visible at right, which grow in eastern Africa at very high elevation. Many cycads may be grown outdoors in California and the southern United States, but they cannot seem to tolerate the less equable climate in other parts of the nation. Many cycads face imminent extinction. Cycads are in danger of becoming extinct both because they live in endangered habitats such as tropical forests, and because they grow so slowly and reproduce so infrequently.
Several species are already extinct in the wild.
Many more are under threat from habitat destruction, and pressure from unscrupulous collectors. However, because of their large attractive leaves, many cycads have found a home in public and private gardens around the world. Breeding programs at several institutions have been undertaken to preserve the various species, but this is made difficult by the necessity of maintaining genetic variation present in natural populations. To protect natural populations, five genera are now covered by international law, prohibitting trade of seeds collected in the wild. All this effort may not be enough to save the cycads from extinction.