While working on postdoctoral studies, I spent several weeks during two trips to the Commonwealth of Puerto Rico, studying the natural enemies of a weevil that was threatening the citrus industry in Florida where it had been accidently introduced. During my visits to the island I had an opportunity to see some of the wild and semi-wild areas of the island, mostly in the Cordillera Central, the Luquillo Forest (including El Yunque) and the Caribbean Coast near Guánica. Although somewhat ignored, Puerto Rico has a very interesting fauna and flora, including 500 native species of trees and at least half that many introduced species. Two volumes cover around 750 species of native and introduced trees. There is also a book covering just the ferns of the Luquillo Forest! I will concentrate in this diary on this diverse flora.
I found Puerto Rico to be a charming island and while I spent much of my time in coffee and orange plantations, even there tropical nature was evident. Basing our operations in the western part of the island on the Mayaqüez campus of the University of Puerto Rico, we ranged to Ajuntas in the Cordillera Central and Isabela in the northwest to Ponce and Guánica along the Caribbean coast and finally to El Yunque on our final days of the second trip. Among discoveries made by the team of researchers were at least a couple of new records and two undescribed species of spider, a colony or two of Red Imported Fire Ants (Solenopsis invicta - first record in Puerto Rico!), and the observation that small ants were among the most important enemies of our target pest. The Red Imported Fire Ants eventually circumnavigated the island, showing up near San Juan within a year or two after our discovery at Ponce! However the island was already host (as I found out at Caña Gorda) of huge numbers of the Tropical Fire Ant (Solenopsis geminata).
The flora, both native and imported, is quite fascinating and certainly beautiful. If I had more time I think I would have explored more of the native plants, but both trips were working excursions and we had to get as much done as we could in between tropical rains - always announced by the calls of the Coquis - tiny tree frogs. However, we did see a lot of country in Puerto Rico's 3500 square miles.
The island has some very picturesque areas, including remnant rain forest. On the trails of the Luquillo Forest I was never free from the sound of running water as the intermittent rain kept torrents rushing down the mountain. In the Cordillera Central there were many streams and small rivers
A tropical forest waterfall along the road in the Cordillera Central.
It was difficult to take photographs on El Yunque as the lighting was very tricky. One of my companions said that the gods of the mountain did not like photographs and in truth only a few of the photographs I took turned out (this was back in the days of the 35 mm film camera and so I could not check out the results instantly as I can now.) The native Tree Ferns were certainly quite different than what I was used to, having grown up in the Sonoran Desert of Arizona, and reminded one of paintings of what the Permian forest must have looked like.
Tree Fern (Cyathea arborea) forest near the summit of El Yunque, Luquillo Forest.
Tree Fern along road in Cordillera Central on way to Adjuntas.
Other native plants, such as the Palma de la Sierra, Heliconias, and Cecropia Trees, were equally strange to this desert rat. However as a biologist I was enthralled. I was able to photograph a Heliconia somewhat past its prime, but the photo was not as sharp as I would have liked.
A native Heliconia in the Luquillo Forest.
Other native plants that I discovered around the island were also quite interesting. The Wild Mamey is quite edible and was among the many species of fruit trees, both native and exotic, to be found on the island.
Wild Mamey (Mammea americana), a member of the Mangosteen family.
A mix of native ferns and imported Impatiens from Madegascar cover a forest floor in the Cordillera Central.
Frangipani (Plumeria alba) along the Caribbean Coast at Caña Gorda.
Although Coconut Palm is thought to have originated in SE Asia, it is now so ubiquitous on tropical beaches worldwide as to be considered native.
Coconut Palm (Cocos nucifera) along the Caribbean Coast near Ponce.
Coconut Palms along Mona Passage.
A palm garden on the Mayaqüez campus of the University of Puerto Rico contained a number of different species, some native and some imported.
A commonly planted tropical SE Asian shrub to small tree is the Butterfly Bauhinia (Bauhinia monandra). The genus, which has partially divided leaves, was named for the Bauhin Brothers, who were both botanists.
Again a tropical shrub planted everywhere, the Hibiscus (Hibiscus rosa-sinensis) varies widly in the color of the flowers.
The Madagascar tree known as the Flamboyant (Delonix regia) is startlingly beautiful. It is planted widely in Puerto Rico and graces the streets of Mayaqüez. This individual was growing in a lot near the campus.
A very strange palm tree from SE Asia and India that is occasionally planted in various tropical areas is the Fishtail Palm (Caryota sp.). This photo shows the unusual strings of fruit.
African Tuliptrees (Spathodea campanulata) are not related to the U.S. Tuliptree, but to the Catalpa.
Flame of the Woods (Ixora coccinea) at Mayaqüez. A member of the Rubiaceae from the East Indies.
A super-sized Crape Myrtle (Lagerstroemia speciosa) from Asia and Australia.
A ornamental shrub related to Oleander, the Golden Trumper (Allamanda cathartica) actually originated in Brazil.
All photos are by me.