Roystonea (Royal Palm) is a genus of 10 species of monoecious palms, native to tropical regions of Florida, the Caribbean, and the adjacent coasts of Central and South America. Named for Roy Stone, a U.S. Army engineer, the genus contains some of the most recognizable and commonly cultivated palms (R. regia) in tropical and subtropical regions.
While royal palms are considered a "tropical" palm, they do grow in favored microclimates in central Florida, e.g. some areas around Tampa Bay and Cape Canaveral. They also will grow - albeit slowly - in favored microclimates in southern California, southern Arizona and the extreme southern Texas barrier islands near the Gulf of Mexico. Royals are being increasingly planted on Galveston Island where they do very well and as far north as Houston where south of Interstate-10 you are beginning to see individuals 20-30 feet tall, unthinkable just 15 years ago.
Royal palms are rather intolerant of cold weather. The foliage will show cold damage at 31°F (-1°C) and the palm will defoliate at 29°F (-2°C). Royal Palms may be killed by temperatures of 25°F (-4°C). That said, seemingly "dead" Royal Palms may occasionally "return to life" after severe freezes in the low 20°F range (-5 or -6°C), but there is usually a trunk constriction that marks the event.
Because their native location is in "hurricane alley", royal palms have adapted to the high winds by easily shedding their leaves. This leaves a bare trunk that more likely to survive a severe storm than a trunk with a full set of leaves. The palms quickly renew their foliage after such an event. On the island of Hispaniola, royal palms are trees favored by Palmchats for feeding, roosting and nesting.
The name "Royal Palm" is widely used in Florida for the name of streets, real estate developments, and the village of Royal Palm Beach.
Researchers from National Center for Scientific Research report details of new studies and findings in the area of hyperplasia animal studies.
Apr 28, 2008; New investigation results, 'Effects of D-004, a lipid extract from the royal palm (Roystonea regia) fruits, tamsulosin and...