ROYAL PALMS

Back during the heyday of henequen or sisal production, when Mérida boasted of being home to more millionaires per capita than any other city on Earth, entry roads to the most elegant plantation mansions often were framed with tall, stately Royal Palms, ROYSTONEA REGIA. You can see the Royal Palms where I am now below:

Unlike the Chit and Thatch Palms at our last two stops, which were fan palms with the fronds' pinnae radiating from the petiole top, you can see that Royal Palms are "feather palms" whose pinnae arise from a long midrib or rachis. You can compare the above Royal Palm's feathery fronds with a fan-type Chit Palm frond at our recently uploaded Chit Palm page at http://www.backyardnature.net/yucatan/chitpalm.htm.

As a group, the genus Roystonea is distinguished by: its tall, columnar, single trunks, or boles; its fronds' pinnae arising at several angles from the midrib so that the fronds look a little shaggy, not neatly flat like a chicken feather, and; having a prominent, green "crownshaft" between the gray bole and its tuft of shaggy fronds.

The above picture shows how the palms' crownshafts are formed by the leaves' very broad, overlapping petiole-bases, the petiole being a leaf's stem.

The bottom leaves or fronds of Royal Palms always are drying up and falling off as new, larger fronds emerge above them. The flaring petiole-base of a frond lying just outside my door, next to my foot-long sandal, is seen below:

Notice how the Royal Palm's gray bole is narrowly ringed horizontally. Those rings are scars from where old petiole bases have fallen. You can see, then, that during its whole life a Royal Palm drops quite a few fronds and petiole bases like the one pictured one. Old fronds fall mainly during the dry season, which we are into now. Ridding itself of older, presumably less efficiently photosynthesizing leaves can be thought of as a water-saving adaptation.

You can see a Royal Palm frond's closely packed pinnae shaggily arising from various angles from the midrib below:

Compare that with pinnae systematically arching at just two angles from the midrib of a Manila Palm at the right.

Why would such dignified palms permit themselves such disorderly appearing fronds? I think I know the answer because each morning I build my breakfast campfire beneath a Royal Palm and all during the meal cool water droplets shower onto my bare back. The droplets fall from the palm's shaggy leaves where water has condensed. Typically at this time of year we have morning fogs; the fronds' multitudinous slender pinnae projecting into the air gather fog droplets and combine them into little streamlets of water that drain down the palm's trunk, as shown below:

These are very modest streams but here during the dry season after a too-dry wet season, maybe such little streams make all the difference to the trees. I wouldn't be surprised to find that most of this trunk-surface water is absorbed into the trunk directly instead of entering the tree via roots.

Three Roystonea species are planted pantropically. There's R. oleracea, the Cabbage Palm originally from the West Indies and with its bole bulging at its base; R. elata, the Floridian Royal Palm from southern Florida, whose bole bulges toward the top producing a "shoulder," and; our R. regia, native to Cuba, and sometimes referred to as the Cuban Royal Palm, with a bole thickening mostly toward the middle.

These variously positioned bole bulges provide extra water storage capacity for the species. I've always wondered why trunks in this species bulge, and now I'm suspecting that they may bulge where they most imbibe water draining down their sides.

With bulging boles, the discarding of older fronds during the dry season, and dew-collecting pinnae, the genus Roystonea is beautifully adapted for surviving severe dry seasons.