"Its lands are most beautiful,
and filled with trees of a thousand kinds,
so tall that
they seem to touch the sky.
I am told that they never loose their foliage.
This I can understand, for I saw them as green

and as lovely as they are in Spain, in the month of May."
    From the log of captain Christopher Columbus (1451-1506),

    upon his discovery of the island of Kiskeya, today known as "Hispaniola"

 


Common Caribbean tree ferns at dusk, Cyathea arborea. El Yunque National Forest, north-eastern Puerto Rico.

 


 

Reaching for the Heavens

 

    Higher plants are those that possess a true vascular system of xylem and phloem that carries water, hormones, nutrients, and wastes to and from the different parts of the organism. This arrangement is analogous to the circulatory system of veins and arteries of chordate animals.

 

    Vascular plants are represented in the West Indies by hundreds of families. The most primitive ones are the ferns and their allies.

 

DIVISION PSILOTOPHYTA: WISK FERNS

 

Family Psilotaceae

 

    These are the simplest of the living vascular plants. In appearance, they resemble masses of erect or hanging green filaments. The leaves are almost microscopic, and their spores are borne in trilobed structures ("synangia") spaced along the thin stems. The living members of the family comprise only two genera and three species. The Pantropical genus Psilotum has two species, one of which is found in the West Indies.

 

Psilotum nudum.

First photograph: Carolina, north-eastern Puerto Rico.

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

 

DIVISION LYCOPODIOPHYTA: CLUBMOSSES AND THEIR KIN

 

Family Lycopodiaceae

 

    There are only two extant genera of these family: the monotypic Phylloglossum of Australia, and the Cosmopolitan Lycopodium, this last with numerous species in the Antilles. These plants sometimes resemble miniature pine trees, with long stems and minute, scale-like leaves. They inhabit humid and wet areas in forests' clearings.

 

Lycopodium cernuum. Sage Mountain National Park, Tortola, British Virgin Islands.



The flimsy and delicate Lycopodium linifolium. El Yunque National Forest, north-eastern Puerto Rico.

 

Lycopodium sp. El Yunque National Forest, north-eastern Puerto Rico.

 

Lycopodium sp. El Yunque National Forest, north-eastern Puerto Rico.



Lycopodium aqualupianum. El Yunque National Forest.



Huperzia aquilupiana.
Carite State Forest, east-central Puerto Rico.



Huperzia dichotoma. El Yunque National Forest, north-eastern Puerto Rico.



Huperzia taxifolia. El Yunque National Forest, north-eastern Puerto Rico.

 

DIVISION POLYPODIOPHYTA: FERNS AND THEIR KIN

 

    A very ancient lineage dating back to the Devonian period, these were the first plants with a true vascular system. Thanks to this advanced array of water- and nutrient-transferring organs, some ferns and their kin were the first plants in planet Earth's geologic history to become tree-size, instead of lying prostrate and close to the ground like liverworts and mosses. (However, most ferns are still rather small and flimsy).

 

    Ferns and their allies have a two stage life cycle. The sporophyte is the larger stage (the one people are familiar with as being a "fern") and produces spores from structures called "sori" (singular "sorus"). Spores give rise to gametophytes (tiny and almost invisible on the ground) which produce eggs and sperm. Gametophytes reproduce sexually through cells analogous to an animal's sperm and eggs, and from that process sporophytes arise, once again.

 

Family Polypodiaceae

 

    Closely related to typical ferns, members of Selaginella grow close to the ground or as epiphytes in many humid habitats of the West Indies. These most primitive of ferns are small plants found in forest understories and clearings.

 

Selaginella krugii. Carite State Forest, north-east-central Puerto Rico.

Members of this genus resemble ferns but are simpler in structure.

 

Selaginella flabellata. Northern Forest Reserve, Dominica. Lesser Antilles.

 

Selaginella flabellata. El Yunque National Forest, north-eastern Puerto Rico.

 

    Ferns are generally small to medium-sized plants. Their life cycles, like those of all filicopsids, comprise two stages: a tiny and inconspicuous gametophyte, and a larger sporophyte which, as the term implies, produces spores. This last stage is the plant that people think of when ferns come to mind. The group is Cosmopolitan in its distribution, and some more than 10000 species are known.

 

Fern, Trichomanes membranaceum. Morne Trois Pitons National Park, south-central Dominica, Lesser Antilles.



Ferns, Pleopeltis sp. Mountaintop, central Saint Thomas, United States Virgin Islands.

 

Dicranopteris pectinata forms almost pure stands in exposed, highly acidic soils in West Indian montane regions.

Central Mountain Range, Dominican Republic, Hispaniola.

 

Ferns, Acrostichum aureum. Rio Grande, north-eastern Puerto Rico.

This species grows in brackish or saline waterlogged soils, usually in or near mangrove swamps.

 

Fern, Macrothelyperis torresiana. Camuy Caverns Park, Camuy, north-western Puerto Rico.

 


Fern, Adiantum tenerum, growing on limestone. Santo Domingo, southern Dominican Republic, Hispaniola.


Fern, Adiantum macrophyllum. Camuy Caverns Park, Camuy, north-western Puerto Rico.

 

Fern, Anopteris hexagona. Ciales, central Puerto Rico.

 

Fronds and sorus of fern, Peltapteris peltata.

First photograph: El Verde Biological Station, north-eastern Puerto Rico.

Second photograph: Guilarte State Forest, west-central Puerto Rico.

 

Fern, Hypoderris brownii. Camuy Caverns Park, Camuy, north-western Puerto Rico.

 


Fern, Odontosoria aculeata. Parque del Milenio, north-eastern Puerto Rico.

This species is a creeping vine in mesic forests.



Fern, Odontosoria scandens. El Yunque National Forest, north-eastern Puerto Rico.

 

Fern, Elaphoglossum simplex. Carite State Forest, east-central Puerto Rico.

 

Habitus and sori of the fern Elaphoglossum maxonii. Carite State Forest, east-central Puerto Rico.



Elaphoglossum crinitum. El Yunque National Forest, north-eastern Puerto Rico.

 

Ferns, Polypodium polypodioides, (with P. astrolepis). Camuy Caverns Park, Camuy, north-western Puerto Rico.

 

Fern, Polypodium phyllitidis, growing on a boulder in the montane moist forest. Crown Mountain, central Saint Thomas, United States Virgin Islands.

An epiphytic and epilithic widespread in the Neotropics.

 

Epiphytic fern, Polypodium aureum. Gorda Peak National Park, Virgin Gorda, British Virgin Islands.

 

Fern, Polypodium heterophyllum. Gorda Peak National Park, Virgin Gorda, British Virgin Islands.

 

Ferns, Thelypteris angustifolia. Ciales, central Puerto Rico.

 

Fern, Thelypteris sancta. Camuy Caverns Park, Camuy, north-western Puerto Rico.

 

Fern, Thelypteris x invisa. Camuy Caverns Park, Camuy, north-western Puerto Rico.

This is a natural hybrid species.



Fern, Ptyrogramma chrysophylla. South-eastern Saba, Lesser antilles.

 

Fern, Lonchitis hirsuta. Camuy Caverns Park, Camuy, north-western Puerto Rico.



Fern, Tectaria heracelifolia. Guajataca State Forest, north-western Puerto Rico.

 

Fern, Asplenium sp. Florida, central Puerto Rico.


Fern, Asplenium cuneatum. The Quill National Park, southern Saint Eustatius, Lesser Antilles.


Fern, Vittaria lineata. The Quill National Park, southern Saint Eustatius, Lesser Antilles.


Fern, Vittaria sp. Vermont Nature Reserve, south-western Saint Vincent, Saint Vincent and the Grenadines, Lesser Antilles.



Fern Acrostichum danaelifolium. Boqueron Wildlife Refuge, south-western Puerto Rico.


Developing fern frond, species undetermined. Guilarte State Forest, west-central Puerto Rico.




Ferns, Hemionitis palmata. Rio Grande, north-eastern Puerto Rico.


Family Cyathaceae

 

    Tree ferns are medium-sized to large plants of temperate and tropical mesic and hydric forests. The family of about 700 known species is Tropicosmopolitan, roughly evenly divided between the New and Old worlds, which may imply that they are a Pangaean lineage. However, their spores are easily carried by the wind, which may help them colonize new areas with ease. Some species are found in temperate regions.

 

    These plants are related to true ferns, and their typical habitat is montane regions of the tropics. They often are among the first plants that people recognize for what they are when they visit any forest where they are found.

 

    A tree fern's "trunk" is actually an erect stem (the "caudex") from the top of which grow its large leaves. Although tree ferns resemble palms the two groups are of course unrelated. Beautiful and elegant trees, these organisms are common in humid and rain forests of the Antilles. Some species attain 15 meters in height. Others scarcely reach a man's height and are part of the forest's understory. Some even lie prostrated on the ground in a lengthwise manner.

 

    The most abundant species in this region is the common Caribbean tree fern, Cyathea arborea, a large species up to 12 meters tall. It is found throughout the West Indies and in northern Colombia. Its immense fronds with a fluffy appearance are very noticeable alongside mountain roads and in wide forest clearings. Many other species - including a high number of local endemics - of this and related genera are found in areas with abundant rainfall in all the larger West Indies.

 

Common Caribbean tree ferns, Cyathea arborea, cover the slopes of many mountains in the West Indies.

For many people, these living fossils epitomize the luxuriant beauty of tropical rain forests around the World.

First photograph: Morne Trois Pitons National Park, south-central Dominica, Lesser Antilles.
Second photograph: El; Yunque National Forest, north-eastern Puerto Rico.

 

The peculiar shape of the developing fronds of tree ferns. This is Cyathea arborea.

El Yunque National Forest, north-eastern Puerto Rico.

 

Tree fern, Cyathea imrayana. Northern Forest Reserve, Dominica, Lesser Antilles.


Tree ferns in the cloud forest, Alsophila bryophylla. El Yunque National Forest, north-eastern Puerto Rico.