Sunday, August 5, 2012

Psychilis monensis some observations of plants "in situ"

This form has a flat open flower with green sepals and petals

Cream colored flowers

Yellowish nodding, slightly cupped flowers
 with lips whose sides curl back
Relatively shorter lip on green flower

An inflorescence with five open flowers

A very pale form with cupped sepals
Seed capsule
The orchid Psychilis monensis is endemic of the island of Mona.  Mona Island sits in the Mona channel which located is between Hispaniola and Puerto Rico.  Mona Island is a deserted island only inhabited by a few personnel of the department of natural and environmental resources of Puerto Rico.  It is visited by fishermen hunters and campers but lately, mainly due to a number of deaths on the island caused by sunstroke, dehydration and accidents, the number of visitors has reduced significantly.  Mona Island is part of the United States, it was ceded to the nation after the Hispano-American war along with Puerto Rico and other islands of the Puerto Rican Bank.
The main terrain in Mona Island is a flat limestone plateau mostly at an elevation of one to two hundred feet above the sea.  The island receives a comparatively low quantity of rain, 30 inches a year, and most of the vegetation is composed of drought resistant plants.  The limestone plateau is a particularly challenging place for plants to grow due the harsh conditions that prevail on it.   Most of the ground in the plateau consists of bare, rain eroded limestone, this terrain can severely damage even the most sturdy footwear faily quickly.  There are trees in the plateau but they are small and occur where there is a pocket of soil in the rocky terrain.  Sunlight is fierce and temperatures high which makes dehydration and sunstroke a constant threat.
In these surroundings, which not in the least resembles what most people think as the ideal orchid growing environment,  Psychilis monensis not only lives but thrives.   In certain parts of the islands plants are downright abundant.  I visited Mona Island in July 2012 and one of my goals was to see this orchid.  I went for a short walk to look for orchids about an hour before sunset, when temperatures are tolerable and sunlight is considerably reduced in intensity.  I found that in a particular area of low shrubs these orchids were exceedingly common.  Many shrubs had Psychilis growing in the middle of them, some of the plants were large specimens.  In the largest plants almost every pseudobulb had an inflorescence.
Psychilis plants were growing everywhere in this area, on the ground, on cacti, on dead or dying trees and on the bare rock.  However plants exposed all the time to full sun were stunted, with reddish leaves and few if any inflorescences.  Plants growing in soil seemed in worse shape than either those in bare rock or growing as epiphytes.  In fact a number of the plants that were located directly in contact with soil were dying or had dead parts.   The largest and healthiest plants were those located one or two feet over the ground on a shrub that shielded the plant from the worst of the midday sunlight and yet allowed a considerable amount of sunlight to pass through.
The flowers of Psy. monensis are surprisingly variable.  I heard a presentation where a student that had done some field research argued that this was due to the fact that they don’t give a reward to pollinators and they need to have variability so that potential pollinators won’t learn to avoid them before pollination is affected.   Unfortunately my camera stopped working on my second day in Mona so I have only a few photos of the flowers of this orchid, taken on a small area near the Sardine Beach.  Nevertheless I saw a bit of the variation that one can see in the whole island.  In the flowers I saw the floral parts could be short or long, perpendicular to the lip or almost parallel to it, green, pinkish white or pale yellow.  The lip could be richly colored, white, long, short, flat or with its sides recurved back.  Some flowers were nodding with the lip hanging straight down and others held the lip almost horizontal.  The inflorescences can bloom repeatedly, I saw one with evidence of having bloomed six or seven times.
No other orchid compares in abundance with Psychilis in Mona island.  You can find a few plants of Domingoa here and there, Oeceoclades in forested areas of the coast and Vanilla, Tolumnia and Broughtonia in particular locales in the interior of the island, but all of the previous orchids have a patchy distribution and, when compared to Psychilis, take an effort to find.  I have read accounts of orchid collectors from the eighteen and nineteen century that remark on finding orchids in the hundreds and even in the thousands growing all over the landscape.  In Mona Island you can still see a glimmer of how a pristine orchid population looked to those early explorers.
 Happily the orchids of Mona Island are pretty safe from human depredations and likely to remain so for the foreseeable future.  The main thing that protects these orchids is that the average orchidist reaction to the flowers of Psychilis is probably “meh”.   The relatively small flowers of Psychilis can hardly compete, in the eyes of an average orchidist, with the very many brightly colored, large flowered hybrids that are currently the norm in the orchid market.  I know that visitors occasionally take plants, but this collecting doesn’t seem to make even the tiniest noticeable dent in this orchid population and must be very light indeed as you can find large plants at a few minute walk from the camping grounds, something that would not happen if any amount of collecting was happening as usually it is the largest and most handsome plants the ones that are collected first.  Without a doubt probably almost all of the plants that have been taken from the island have died.  In all my years of orchid growing I have only seen a single plant of Psychilis monensis growing successfully out of Mona Island.  It was twenty years ago in Cupey, in the garden of a non-orchidist that had tied the plant to a wooden post in his garden when he had arrived back from a visit to Mona and had subsequently given it absolutely no care or attention to it.  I have heard that there are a few plants in cultivation, but unlike Psy. kranzlinii, Psy. macconellia and Psy. krugi which show up regularly in orchid shows, I have yet to see a Psy.  monensis at a show.  My suspicion is that Psychilis monensis just can’t survive the way in which most orchidist treat their plants as it is radically different from what these plants experience in their natural habitat.
This Psychilis is so common in its habitat because it is supremely well adapted to conditions that few other plants can tolerate.   In the coastal areas of Mona, where conditions are much more moderate you are hard pressed to find plants of Psychilis growing anywhere.   These plants have adapted to high levels of sunlight, strong desiccating winds and weeks or even months without any measurable rain.    Move a plant such as this to a shady, humid spot with stagnant air where it gets drenched with water every two or three days and im all probably it won’t survive, particularly if its roots are buried in bark and kept wet all the time.  So my advice is simple, leave these plants in its natural habitat.

Large plant with many inflorescences

A common hazzard in Mona Island

Psychilis monensis inflorescenses can rebloom several times


Unknown said...

Obrigada Ricardo por compartilhar

Unknown said...

Super interesante.muchas gracias por la publicacion de este articulo al sr Valentin

Ricardo said...

De nada! Una de mis actividades favoritas es observar la naturaleza, otra es compartir mis observaciones con otros con el mismo interes.