Domingoa haematochila (Rchb. f.) Carabia 1943, in situ in Mona Island in the Caribbean

This flower opened in the morning after a spell of strong rain

A whole plant view.  This plant had five inflorecenses, two with flowers.

For many years, in the eighties and nineties, I used to visit Mona Island on a yearly basis.   One of the things that lured me to Mona was that it is full of many interesting species of plants and animals.   I was particularly intrigued by the orchids of Mona.  The environment of Mona Island is not one that most people would associate with orchids. 

Most of the island is a plateau composed of limestone.  Here and there are pockets of soil in which shrubs and trees eke out an existence but most of the surface is bare limestone.  Rainfall is seasonal and can be scant, weeks, sometimes months, can go without measurable rain.   Temperatures can rise over 100F out in the plateau, I still remember my surprise (on a previous visit) when a thermometer I carried with me on a walk during the hottest time of the day measured 120 F.   The dominant vegetation on the plateau is shrubs, cactus and low trees.  There are places where the limestone has eroded to the point that sunken depressions have formed and accumulated a layer of soil where more substantial trees can grow.  But almost all of these depressions are small.  One of the largest one, the Bajura de los Cerezos has large trees and is moister than the surrounding terrain.  Domingoa in Puerto Rico lives in this severe but beautiful environment.

The last time I visited Mona Island, around 1996, I found many stemmed plants of Domingoa in the moister environment of the “bajuras”.  I had also found plants in the hot and very sunny plateau, but those were much smaller and much less common than the ones in moister surroundings.   In particular I found a good sized plant within easy walking distance of the camping area.   Sadly, the photos I took of the plant at this time were not good.

I visited Mona again between the 20 and 24 of July of 2012.  It was a wonderful experience.  One of the first things I did was to seek out the Domingoa plant to see if still survived.   I went looking for the place where I had seen it last and sure enough the plants were there.  I was dismayed by the fact that all the plants I found had developing buds or spent flowers.  Not a single one had an open flower.  However, one of the nights there was a spell of rain, the next day I found an open flower.  The plant I found had five inflorescences, one with a newly opened flower another with a bud just opening and one with a tiny developing flower bud.

Unlike many orchids Domingoa is pretty secure from collecting pressures.  Most of the island is off-limits to visitors and, even in those places where hiking is allowed, high temperatures, fierce sunlight and hordes of mosquitos tend to keep away all but the very hardiest of hikers.  I don’t know if Domingoa plants are in cultivation on the island of PR, I don’t recall ever seen plants exhibited in local orchid shows.  Domingoa haematocheila is reported from Cuba, Hispaniola and Puerto Rico. Ackerman in  his book An Orchid Flora of Puerto Rico and the Virgin Islands reports that the forms from Mona are vegetatively much smaller than the forms from Cuba.