Consisting mostly of shale, mudstone, sandstone, and limestone bedrock, the Blue Mountains are mostly at an elevation of greater than 3500 feet, and peak at 7402 feet. They consist of several vegetation communities that vary in levels of anthropogenic disturbance. The southern slopes below 5250 feet have mostly been cleared of forest and now are either fallow fields or are used to grow coffee, vegetables, or ornamental plants.
The Blue Mountain forests are diverse and vary depending on elevation. On the northern slopes below 2950 to 3300 feet, trees grow to a height of 100 to 120 feet, and woody vines are abundant. This area is known as the lower montane rainforest. At elevations above the lower montain rainforest is what is known as the upper montain rainforest, an area characterized by heavy fog. Within the upper montain rainforest, elfin woodlands are located between 6500 and 7400 feet, and are characterized by shorter trees and many lichens and mosses. Below these areas are forests made up of taller trees.
Many of the openings created for agriculture and tourism have been colonized by weeds from Europe and North America; there are also abundant native weeds in these disturbed areas. Spanish needles (Bidens alba) is one such native weed.
Another, and one of my favorite weeds of the trip, is Cupid's paintbrush (Emilia fosbergii).
Most of the plants found in the undisturbed areas of the Blue Mountains, however, are native to Jamaica. In fact, 50% of the flowering plants within Blue Mountain forests are endemic to Jamaica, meaning that they are found growing naturally only in Jamaica. Of these endemics, 30 to 40% are only found in the Blue Mountains! One of those endemics is begonia (Begonia minor), a shrubby plant that grows on exposed rock cliffs.
Because we were bicycling down the mountain, we didn't have as much time as I would have liked to observe and study the flora and fauna of this beautiful area. If we ever make it back to Jamaica, we have agreed that we would like to spend much more time exploring the Blue Mountains.
Most of my information comes from A Guide to Plants in the Blue Mountains of Jamaica by Susan Iremonger.