Visitors to the Brac Parrot reserve will likely pass by a very special flower that is found only in the Cayman Islands.
One of the 26 varieties of native orchids, the wild banana orchid (Myrmecophila thomsoniana) is Cayman’s National Flower. According to literature provided by the National Trust for the Cayman Islands, the orchid comes in two varieties: Myrmecophila thomsoniana var. thomsoniana, which originated on Grand Cayman, and Myrmecophila thomsoniana var. minor, which came from Cayman Brac and Little Cayman.
The Trust notes that the flower can be found blooming in woodlands as well as in gardens throughout the islands, with its distinctive shape often seen adorning trees near houses.
According to the Trust, both varieties have scented flowers with purple lips. The petals are predominantly white on the Grand Cayman variety, while the Sister Islands’ variety has slightly smaller flowers with pale yellow petals.
“Before international trade in wild orchids became regulated, wild banana orchids were occasionally exported from Cayman Brac, and many specimens were also brought to Grand Cayman,” the Trust notes.
“As a result, some hybridization has occurred and some variation in flower color can now be seen in Grand Cayman, particularly in garden plants.”
The Trust literature states that the wild banana orchid is an epiphyte, which means that it grows on another plant but does not harm it in the way a parasitic plant would.
“Its tiny seeds are dispersed by air currents,” the Trust notes. “They settle and germinate on a host plant, usually a tree with rough bark such as a whitewood, mahogany or logwood. The growing orchid clings to its host’s bark by its roots, which absorb water and nutrients from the rain when it runs down the branches and trunk of the supporting tree.”
Wild banana orchids like humid conditions, for example, woodlands downwind of ponds and wetlands.
“As the plant grows, its distinctive shape can be seen developing. Clusters of long, finger-like pseudobulbs group together at the base of the plant, resembling bunches of bananas,” the Trust notes.
“Long graceful flower spikes appear around April and May each year, though occasionally flowers can also be seen at other times of the year.”
During the drier winter, the orchid rests between flowering seasons to maintain its flowering period. During this time, the bulbs dry out and become compressed. In the rainy season, the pseudobulbs plump up and the flowering begins again.
“Plentiful rain ensures good conditions for seed germination. One orchid can release as many as one million seeds [which] are dispersed at random, and very few will by chance end up in a suitable place to grow.”
The Trust notes that many orchids have very specialized requirements for successful growth and reproduction. Close relatives of the wild banana orchid, which are found in Central and South America, harbor nests of stinging ants in their hollow pseudobulbs. The ants protect the orchid from plant-eating creatures of every kind, in return for which the orchid provides a dry and secure home. The plant also seasonally exudes sweet nectar from a gland on the flower spike, which the ants eat.
While the Cayman Islands’ wild banana orchids have the same hollow pseudobulbs and nectar glands, the matching ant species are nowhere to be found. However native anole lizards climb the flower spikes and lick the nectar glands instead.
According to Caymanian folklore, resourceful early settlers found the pseudobulbs occasionally useful as temporary pipe bowls; hollow dried almond twigs made the stems.
The Trust raises concerns that while the wild banana orchid is not endangered, accelerating deforestation for real estate development has meant the loss of many host trees and their orchids.
“Property developers are encouraged to look at established native trees on a site, and retain as many as possible for incorporation into their landscaping schemes,” the Trust advises.
In a September 2016 posting on his NatureNotes 19n79w blog, Brac naturalist Wallace Platts noted that theft of wild banana orchids and other rare plants is also becoming a problem. He warns that international plant thieves pose a threat to the Brac’s indigenous plants as removing them from the wild means they are lost forever.
“Banana orchids were recently stolen right out of West End Community Park for sale to the public on Cayman Brac. They were ripped from the trees by the roots, right on the nature trail,” he says.
The Trust notes there is also some concern that cross-pollination with introduced species may, in time, represent a threat. Fortunately, the Cayman Islands has an active group of orchid enthusiasts who are monitoring this situation very closely.