MacConnell's butterfly orchid, Psychilis macconnelliae. Sandy Point National Wildlife Refuge, south-western Saint Croix, United States Virgin Islands.

Beautiful Sex

DIVISION MAGNOLIOPHYTA: THE FLOWERING PLANTS

    The magnoliophyte organisms (also known as Angiospermae) comprise the vast majority of the members of the Kingdom Viridaeplantae. These are the most adaptable and varied of all autotrophs. They can be found in every terrestrial environment that is not continually covered by snow, and have invaded freshwater and oceans as deep as the shallower parts of continental and insular platforms. A few species are even found in Antarctica but, of course, it is in the tropics where they really come into their own in terms of species.

    Flowering plants possibly arose during the late Jurassic Period. They are the main, most complex and widespread kind of chlorobionts in the majority of terrestrial ecosystems on Earth. Their distinguishing trait, and that which sets them apart from the pinophytes, is that their eggs are enclosed in a chamber prior to fertilization, so the spermatozoids contained in the pollen initially have to migrate to them after pollination occurs.

    Flowers are an elaboration a higher plant's reproductive system: its genitals.

    The beautiful colors and the fragrances (not always appealing to human noses) of many flowers evolved as means to entice, by sight and smell, those potential distributors that might become instrumental in taking the plant's pollen (containers of its sperm) to the stigma so it can eventually fertilize the eggs in the flower's ovaries. That said, many flowers need only wind in order for pollination to occur. Such are often small and inconspicuous. But flowers that are yellow, orange, red, or purple are usually pollinated by diurnal animals like birds and insects. Sometimes hordes of flies, bees, butterflies, honeycreepers, and hummingbirds can be seen feeding on plants with such flowers. Many of these animals are able to see well into the ultraviolet range of the electromagnetic spectrum. Even flowers of subdued colors may appear to them much more vivid than to us.

Heliconia caribaea. Northern Forest Reserve, Dominica, Lesser Antilles.

Red, orange, and yellow flowers like this one are often pollinated by birds and diurnal insects.

    On the other hand, flowers that are white or pale yellow in color most often attract nocturnal animals, like moths and bats. Many such flowers, odorless during the day, will exude strong odors during the night in order to attract their pollinators.

Irlbachia frigida. Mount Soufriere, northern Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.

White and otherwise pale flowers of this kind frequently rely on nocturnal pollinators to produce fruits and seeds.

    Many flowering plants have evolved the capacity to develop fruits. These are covers of fleshy tissue enveloping the seed covers. It should be noted that a fruit provides no direct advantage to the plant, and it would be a total waste of energy for it to develop and sustain an otherwise useless hunk of living tissue... if it were not for its immense indirect benefits.

    Enter metazoans: the animals, unwitting participants come into the reproductive scenario of plants. Indeed, the only reason why a plant invests any energy at all in producing a fruit is to bribe some animal or another into taking its seeds somewhere else. (Along the same line, the reason for the existence of nectar is quite similar: it is an energy-laden "reward", created at the expense of the plant and offered to the appropriate animal, in its case as an exchange for pollinating services).

A bananaquit, (Puerto Rican race, Coereba flaveola portoricensis), and a Puerto Rican bullfinch, (Loxigilla portoricensis), feed on the fruits of Clusia rosea.

Maricao State Forest, western Puerto Rico.

A male purple-throated carib, Eulampis jugularis, shakes off the pollen of a Heliconia, which has stuck to its plumage while it fed on the plant's nectar.

Plants make use of this and other pollinators to spread their own kind.

Eggleston, south-central Dominica, Lesser Antilles.

    As the animal delights itself with the tasty fruit, it will be more likely to leave the seeds - the one thing that really matters - alone and undamaged, and with a chance to germinate later, ideally in some convenient spot away from the parent plant.

    In order to conserve energy, plants produce fruits with just enough volume to tempt the appropriate animal. Thus, most fruits tend to be rather small, with no extra effort invested in anything larger. The huge mangoes, watermelons, avocadoes, tomatoes, grapefruits, and soursops that we see in the grocery store are a consequence of selective breeding and hybridization controlled by man. Such large fruits do not occur in natural populations. They would be there an intolerable waste of resources.

    In a manner similar to flowers of the same colors, red and orange fruits are designed to attract diurnal birds as well as reptiles like large iguanas and tortoises (and, where they are found, mammals with color vision like monkeys, lemurs, and man). These will consume the fleshy parts of the fruit and then discard or excrete the seeds far away from the parent plants, thus helping their kind in spreading into new areas.

Fruits of two Eugenia sp. Cambalache State Forest, northern Puerto Rico.

    Because a fruit only serves its true purpose when a suitable disperser lives in sympatry with it, many plants that live in regions (like the Antilles) with few or none of such such animals have "de-evolved" in their fruit-bearing capacity while their relatives in the continents have retained it. Since the terrestrial sloths and many of the larger rodents are now extinct in the West Indies, many fruit-bearing plants there can now rely only on birds, bats, iguanas, and man for the dispersal of their seeds.

    If fruits are intended to entice animals to disperse a plant's seeds, then why would some plants produce fruits which are poisonous, to begin with? After all, a potential disperser of seeds is of no use if the plant manages to kill its unwilling cooperator before it fulfills its job.

    The mystery is at least partly solved by the fact that plant toxins usually affect only some animals - particularly those liable to destroy the seeds as well as the fruit - while the intended dispersers are immune to it. The case is proven in the Antilles by euphorbiacean trees like the manchineel (Hippomane mancinella) which sweet and fragrant fruits are deadly to humans and most other large mammals, who are likely to swallow the entire fruit and digest even the seeds. But other animals, like Cardiosoma land crabs and Cyclura rock iguanas, eat them with total impunity, after which they discard or defecate the seeds intact. (These animals' flesh might then become toxic to, say, humans who occasionally eat them, in a way similar to how some butterfly caterpillars ingest and incorporate into their own tissues toxins from their larval food plants, thus even as adults becoming unpalatable to birds and lizards).

    The use of poisons likewise occurs in many plants to protect their space and defend parts of themselves other than their seeds. Some even have actual envenomating mechanisms, like thorns, spines, and stiff hairs, like those of stinging nettles, designed to inject toxins into, and thus repel, their would-be predators.

CLASS LILIOPSIDA: THE MONOCOTYLEDONS

    A cotyledon is an embryonic leaf, containing, or having access to, the nourishment needed by the embryo itself. It may turn green as the seed opens and the seedling begins its photosynthetic life.

    As the name implies, monocots are flowering plants with only one cotyledon to each seed. They frequently have a parallel venation in their leaves, which themselves tend to be elongated and lance-like. However, some groups, like araceans (philodendrons and relatives) have a reticulated venation system. The flower parts of monocots exist in multiples of three.

    Some members of the group, namely grasses like corn, rice, and wheat, are among the most important crops cultivated by man. Others, like bananas and relatives, have been domesticated for their fruits, while palms are well-known trees that, with other liliopsids like lilies, irises, and orchids, are valued for their ornamental qualities.

    Although by far most members of this group are terrestrial, a few families include members that are truly marine. These grow on submerged, sandy or muddy soils in the shallow waters of coastal and estuarine environments, including those of the Antilles. They include the "manatee grasses" and "turtle grasses" of the genera Ruppia, Syringodium, and Thalassia.

Family Agavaceae

    This family is represented in the West Indies mainly by Agave, of littoral ecosystems and other mostly xeric environments. This large genus contains about 200 species, all of them with woody stems so short that the leaves seem to sprout straight from the ground. These plants can be very large, and their leaves are often armed with fearsome spines.

    As the proper conditions arise, whole groups of them bloom simultaneously from spikes several meters tall, painting the landscape with yellow or orange. Once they flower, each plant dies, and since they take so long to grow to this climax, they have been called "century plants" by some Caribbean peoples.

Puerto Rican agave, Agave missionum. Little Dix Bay, Virgin Gorda, British Virgin Islands.

Puerto Rican agaves bloom in early summer.

During this dry season, their abundant nectar are a source of nourishment and water for hordes of insects and birds.

Virgin Islands National Park, Saint John, United States Virgin Islands.

Agave intermixta. Bahoruco National Park, south-western Dominican Republic, Hispaniola.

Furcraea tuberosa. Maricao State Forest, western Puerto Rico.

Family Amaryllidaceae

    This is a group of plants that resemble lilies, and several members are found in xeric and mesic areas in the Antilles. Members of Hymenocallis typically produce large, spindly, white flowers. The genus exists from the southern United States to northern South America, and the West Indies.

Caribbean white "lily", Hymenocallis latifolia. Guana Island, British Virgin Islands.

These are sometimes called "spider lilies" for their long, spindly petals and stamens.

Family Araceae

    The family Araceae comprise genera like Philodendron, Dieffenbachia, and Anthurium. Some of these are terrestrial or epiphytic plants of forests' understories. Philodendron are vines that ascend up trees and boulders. Dieffenbachia are terrestrial and produce a highly irritating watery sap. Some members of Anthurium are terrestrial while other, smaller species are commonly seen among bromeliads and orchids as part of the epiphytic communities in mesic and hydric forests.

    Characteristically, members of this group produce tiny flowers and fruits that are borne on spikes. Many have been domesticated by man to serve as ornamentals.

Philodendrum giganteum. Rio Abajo State Forest, central Puerto Rico.

Family Arecaceae

    Palms are distributed through the entire World except the Arctic regions, and are most common and varied in the tropics. They are shrubs, vines or, most often, un-branched trees, some of great height. Some of the most picturesque species in the West Indies are those of the genera Roystonea (the huge royal palms of the Caribbean) and Sabal (palmettoes). (The coconut palms that are so common in Antillean beaches were introduced there from the Indo-Pacific region, and are not treated here).

First photograph taken at the Carite State Forest, east-central Puerto Rico.

    Lesser Antillean Geonoma palms are very unusual within their kind. Instead of being physically self-supporting, they are epiphytic vines that climb up the trunks of rain forest trees.

Family Bromeliaceae

    Bromeliads - the best known of which is Ananas comosus, the pineapple - comprise a family that is exclusively American, save for a lone West African species. Like many orchids, the majority of species are epiphytes, and are most common in tropical latitudes. They be phenomenally abundant in Antillean montane forests.

    Many species accumulate water at the bases of their whorls of leaves and thus serve as breeding areas for many sorts of animals, including mosquitoes, crabs, and frogs.

Bromeliads, Vriesia macrostachia. Carite State Forest, east-central Puerto Rico.

Family Commelinaceae

    The plants included in this group are mainly succulent herbs of forests' understories. Some are planted as ornamentals in many areas.

Commelina erecta, a herb distributed throughout the tropical and warm-temperate Americas, as well as in the African tropics.

The third petal of this flower is transparent-whitish and vestigial.

San Juan, north-eastern Puerto Rico.

Tradescantia zanonia. Camuy Caverns Park, Camuy, north-western Puerto Rico.

Family Cyclanthaceae

    This Neotropical group is composed of rather small plants which take the form of shrubs or lianas. The leaves of some genera resemble those of palms. Their pollination often occurs with the help of beetles and similar insects.

Asplundia insignis. Vermont Nature Reserve, south-western Saint Vincent, Lesser Antilles.

Family Cyperaceae

    Sedges superficially resemble grasses. They are aquatic or terrestrial and produce agglomerated inflorescences. Several species of Cyperus are common in Antillean wetlands and cloud forests, and some species are quite large and used as ornamentals around man-made ponds.

Cyperus elegans. El Rosario, south-western Puerto Rico.

Cyperus odoratus. Las Limas Private Nature Reserve, Guayama, south-eastern Puerto Rico.

    Belonging to the same family as Cyperus, some sedges of the genus Scleria are called "razor grasses". The name derives from their long leaves bordered by minute but sharp serrations. These truly obnoxious plants border the sides of trails in many areas, and are the bane of hikers who have to walk through them in short pants.

Razor grass, Scleria scindens.

Named so because the serrated edges of its leaves can easily cut the skin of an unwary person.

El Yunque National Forest, north-eastern Puerto Rico.

Seeds of razor grass, Scleria latifolia. Grand Etang National Park, central Grenada, Lesser Antilles.

Carex polystachia. El Yunque National Forest, north-eastern Puerto Rico.

Mountain spike-brush, Eleocharis montana.

First photograph: Carite State Forest, east-central Puerto Rico.

Second photograph: El Yunque National Forest, north-eastern Puerto Rico.

Family Heliconiaceae

        Common both in lowland and highland humid and rain forests of the Antilles (and of much of the Neotropics) are plants of the genus Heliconia. Relatives of the banana (family Musaceae) these plants produce showy flower bracts usually in some tone of yellow, orange, or red. Some species are known as "lobster claws", for the shape of their inflorescences.

    These are some of the most picturesque plants in Antillean rain forests, and many varieties have been cultivated and hybridized with ornamental purposes. Some species, like Heliconia caribaea and H. bihai, have developed a number of morphs varying in color and shape depending on the island, and even within regions in the same island. Eventually, some of this may turn out to be full species.

Family Hypoxidaceae

    These are small herbs related to lilies and irises, with bright flowers. Hypoxis are found in the understory and clearings of mesic West Indian forests. The genus is widespread in tropical and temperate regions of the World.

Hypoxis sp., (possibly H. wrightii). Blue Mountains, east-central Jamaica.

Hypoxis sp. Carite State forest, east-central Puerto Rico.

Family Marantaceae

    The arrowroot family is here represented by genera like Calathea. Similar to Heliconia plants, the underside of the leaves of some species are covered in a waxy substance used in some places to prepare polishers.

Family Orchidaceae

    The flowers of God.

    The apex of chlorobiontic evolution, orchids comprise the second largest group of flowering plants. Distant relatives of the lilies and, perhaps surprisingly, of the asparagus, these plants number more than 25000 known species, and are the largest monocot family. Only asteraceans (treated in the section on dicots) surpass them in numbers of species among living plants.

    Orchids are found in every terrestrial region on Earth except Antarctica and places covered by perpetual snows.

    Ordinarily, orchids have three petals and the same number of sepals (some have lost some of these parts, as a derived character) and have evolved a structure unique among plants: the "column", formed by the fusion of the style, stigmas, and stamens of their flowers. This is the main distinction of their kind, and the way you could recognize an orchid among all other plants.

Column of Epidendrum boricuarum. This structure is composed of the fusion of several flower parts, and is the hallmark of all orchids.

El Yunque National Forest, north-eastern Puerto Rico.

    Famous for their exotic appearance, many orchids are coveted, cultivated, and hybridized by man for their beauty. However, most are actually small plants with correspondingly small flowers. Unlike other plants in the Caribbean, which are pollinated by butterflies, bees, bats, birds and, perhaps, even lizards, most orchids in the Antillean region either depend on wind, moths, and flies to get pollen to their stigmas, or self-pollinate. This last is the case in cleistogamous species. In these last, the flowers never open and fecundation occurs inside the closed bud itself. Some species in the Greater Antilles (like a few Oncidium, shown above) have flowers that mimic the males of certain bees. It is believed that the real insects attack their "rivals" and thus help release the pollen of the flowers onto the stigmas.

    Although many Antillean species of orchids are from common to abundant, some have been decimated by uncontrolled collection from the wild.

    Five subfamilies of orchids are usually recognized, and three are found in the West Indies.

Subfamily Epidendroideae

    This subfamily of orchids is larger than all the others combined. It contains more than 15000 species in hundreds of genera. The group is difficult to classify, but generally shares these traits: they are monandrous (possess one fertile anther); their leaves are distichous or arranged in a spiral; they have hard, waxy pollinia; and the ovary has a single locus.

    By far, most species are epiphytic, and are especially common in tropical forests around the World. Epidendroids conform to the archetypal "orchid" that comes to the minds of most peoples.

    The largest orchid genus (and one of the largest genera on Earth) is the one that gives the entire subfamily its name. They are "the ones that live on trees": Epidendrum. These American orchids are especially common in montane regions of the Neotropics. Collectively known as "star orchids", the appearance of their flowers vary from tiny, greenish, and unimpressive to some that are truly large and showy. A related genus Cattleya, is widely cultivated for their beautiful, gigantic, and sometimes otherworldly flowers.

    Many other genera of epidendroid orchids are found in the West Indian region. Some of them follow.

Orchid, Isochilus linearis. Guilarte State Forest, west-central Puerto Rico.

Orchid, Stelis repens. El Cortico, Bahoruco Mountains, south-western Dominica Republic, Hispaniola.

(Photograph courtesy of Mr. Pedro Genaro Rodriguez).

Orchid, Maxillaria coccinea. Syndicate, north-central Dominica, Lesser Antilles.

Orchids, Dendrophyllax sallei. Bahoruco National Park, south-western Dominican Republic, Hispaniola.

(First photograph courtesy of Mr. Pedro Genaro Rodriguez. Second photograph courtesy of Mr. Miguel Angel Landestoy).

Orchid, Dendrophyllax ariza-juliae. Bahoruco National Park, south-western Dominican Republic, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Orchid, Trichopilia fragrans. El Cortico, south-western Dominican Republic, Hispaniola.

(Photograph courtesy of Mr. Pedro Genaro Rodriguez).

Krug's butterfly orchid, Psychilis krugii. Guanica State Forest, south-western Puerto Rico. Another Puerto Rican endemic.

The entire genus Psychilis is endemic to the Antilles, and includes some of the most beautiful orchids in the region.

Dod's butterfly orchid, Psychilis dodii. Peravia, southern Dominican Republic, Hispaniola.

(Photograph courtesy of Mr. Pedro Genaro Rodriguez).

Macconnell's butterfly orchids, Psychilis macconnelliae. Guana Island, British Virgin Islands.

Butterfly orchid, Psychilis rubeniana. Los Haitises National Park, northern Dominican Republi, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Orchid, Broughtonia dominguensis. Puerto Escondido, south-western Dominican Republic, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Pleurothallis compressicaulis. Masiff de la Hotte, south-western Haiti, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Orchid, Ida barringtoniae. Masiff de la Hotte, south-western Haiti, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Orchid, Ionopsis utricularioides. Florida, central Puerto Rico.

Orchid, Ionopsis satyrioides. Florida, central Puerto Rico.

Orchid, Quisqueya ekmanii. Bahoruco Mountains, south-western Dominican republic, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

Orchid, Quisqueya holdrigei. Bahoruco Mountains, south-western Dominican republic, Hispaniola.

(Photograph courtesy of Mr. Eladio M. Fernandez).

    Not all epidendroids are epiphytes. A good number of them are terrestrial in both mesic and xeric habitats. Examples of such species are shown below.

Subfamily Orchidoideae

    These mostly terrestrial plants possess a single fertile anther (they are "monandrous"). The type genus, the Old World Orchis, gives its name to the whole family. Most members of this group are terrestrial, with but a few epiphytic species. The majority of Caribbean species produce white flowers.

Orchid, Habenaria monorrhiza. Toro Negro State Forest, central Puerto Rico.

Orchid, Spiranthes sp. Ebano Verde Scientific Reserve, central Dominican Republic, Hispaniola.

(Photograph courtesy of Mr. Pedro Genaro Rodriguez).

Orchid, Cranichis tenuis. Maricao State Forest, western Puerto Rico.

Orchid, Cranichis galatea. Aceitillar, south-western Dominican Republic, Hispaniola.

(Photograph courtesy or Mr. Miguel Angel Landestoy).

Orchid, Cranichis muscosa. El Yunque National Forest, north-eastern Puerto Rico.

Orchid, Prescottia oligantha. Barbecue Bottom Road, north-central Jamaica.

Terrestrial orchid, Microchilus hirtellus. Florida, central Puerto Rico.

Inflorescences of the terrestrial orchid, Microchilus plantagineus. El Yunque National Forest, north-eastern Puerto Rico.

Subfamily Vanilloideae

    This group contains several genera distributed throughout the World's tropics. In the Antilles the most commonly seen members are those of the genus Vanilla. The seed pods of some of these produce the sweet substance and fragrance that is known from a variety of ice creams and other deserts.

Family Pandanaceae

    Pandanus plants superficially resemble palms. They can be found mostly on karstic forests, growing in forest clearings and road banks.

Pandanus utilis. Camuy Caverns Park, Camuy, north-western Puerto Rico.

Family Poaceae

    Grasses are relative newcomers in the evolutionary history of plants, and arose during the Tertiary Period. Most of the 9000 known species are the small plants known from prairies and the understories and gaps in forests. Some, however, are very large and woody, as are the giant bamboos (Bambusa) of Asia. (Several small relatives of these last are found in the West Indies). Very few species have beautiful inflorescences or are even attractive, but they still are among the most important of chlorobionts.

    The seemingly humble grasses are immensely valuable plants on a planetary scale, since their arrival in the geologic history of Earth allowed for the evolution of another great group of organisms, namely ungulates: the hoofed mammals (modern sheep, goats, antelopes, and cows) which are essential components of many ecosystems and are at the center of many of mankind's economic enterprises.

    More directly influential on man's affairs, some grasses are of paramount importance ever since humans learned to domesticate plants, which in turn allowed them to cease being nomads and to settle in cities, instead. The powerful Egyptian, Assyrian, Persian, Babylonian, Roman, and Macedonian empires of the Old World existed mainly because of their ability to consistently raise crops of wheat, barley, and oats: all of them grasses. Further to the east, the great Oriental civilizations that developed in what are today China and Southeast Asia owed their existence to another plant that today surpasses every other in terms of total harvested and consumed mass, and which is a grass that grows on swampy areas: rice. And in the New World, the impressive military and cultural empires of the Inca, Toltec, Maya, and Mexica (these last are those erroneously known as "Aztecs") owed much of their power to the domestication of an American grass: maize. Not only do the products of these plants still occupy a center at modern man's dinner table, but those of another genus of grasses have modernly also been cultivated to sweeten his life: Sacharum - sugar canes.

Family Typhaceae

    Members of Typha are known as "cattails", and grow on swampy areas. They produce long spikes of closely packed flowers, indeed resembling the tail of the domestic feline. Typha is indeed the only genus of the family (making this last monotypic). Several of these plants have edible parts, and as such they are used by humans in certain parts of the World.

Typha domingensis. Camuy, north-western Puerto Rico.

Family Zygiberaceae

    This is the group that includes crops like ginger and other similar species. Many are small- to medium-sized herbs of forests understories, superficially similar to heliconias. Some produce masses of beautiful bulbous flowers.

Renealmia jamaicensis. San Lorenzo, east-central Puerto Rico.

Renealmia pyramidalis. Mount Soufriere, northern Saint Vincent, Lesser Antilles.