Roystonea regia

Roystonea regia. 'Cuban Royal Palm'
Left - seen here in Cranbrook Flower Forest on the north coast of Jamaica planted in a stately avenue. I have seen this palm planted this way many times in different countries; there is a wonderful avenue in Singapore Botanical garden. 
Right - a fascinting planting in the Santa Cruz Palmetum on Tenerife, as explained to me by one of it's creators and current manager Carlo Morici. These two specimens were planted at the same time - the one on the right was imported from Florida already with 1.5m of trunk at great expense, and the one on the left was bought as a small 2 year old plant for a few Euros from a local supplier. Please click on the photos for large image - a must.

These specimens are growing in a small town in the south of Thailand and probably in their peak growing years. As with most palms there is a period of slower growth when they are establishing a trunk and then rapid growth in what must equate to their 'teenage' years and then a slowing a little as they get closer to their mature height of about 25m. These specimens are showing only a slight 'belly' in the middle of their trunks which is a vriable characterisitic of the species; the ones in Jamaica (above) have almost no mid trunk swelling. It is possible to see them with more pronounced swelling than these Thai specimens and also with swollen bases to the trunks.

Left - these plants in the Santa Cruz Palmetum exhibit the curvature of R. regia trunks very well. The plant in the centre of this photo has a flower emerging from the base of it's crown shaft (the smooth green area of trunk below the leaves and above the grey trunk). The fan palms in front of these 'Cuban Royals' are a Pritchardia species, (will confirm which one).
Right - This photo shows clearly the smooth crown shaft and a flower standing upright still covered in its tough protective sheath or bract. You can also see an old flower and an old dried leaf base hanging below the crown shaft which illustrates the succession of growth in the crown.

The crown shaft is made up of the bases of the leaves in the crown, the oldest leaf in the crown is the one whose leaf base we can see, wrapped around the trunk. As the leaf dies it's base shrinks and peels back from the crown shaft, eventually dropping off. New flowers grow inside the crown shaft between the layers of leaf bases and as an old leaf drops the flower is revealed in a protective sheath as seen here, the sheaths then drop and the flower emerges. Rapidly growing species such as this produce a large amount of litter and require regular maintenance. The leaves which can be up to 4 m long can be quite a serious health hazard when falling from a height 20m, as can the woody bract and even old flowers and fruits.

Last set of photos above courtesy of Peregrin on flickr.com, see their link on our Resources Page.