United States visas were issued to 8.9 million foreign nationals visiting the United States and to 482,000 immigrants in 2012. A foreign national wishing to enter the U.S. must obtain a visa unless he or she is.
Known for its showy flowers, the genus Mandevilla includes plants that were formerly called Dipladenia. There are about 100 species of this tropical American woody vine. Most species overwinter only in the tropical South.
If separate staminate and carpellate flowers are always found on different plants, the species is called dioecious. A 1995 study found that about 6% of angiosperm species are dioecious, and that 7% of genera contain some dioecious species.