| What are Bromeliads? |
What are Bromeliads?
Bromeliads are plants belonging to the family Bromeliaceae, pineapple family.
Some basic information is compiled in the following:
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| Introduction |
The bromeliad family is currently divided into 50 genera, presently estimated at totaling 3000 species.
The family was first studied and named in the 17th Century by the Paulist Priest Charles Plumier in honor of the Swedish physician and botanist Olaf Bromel (1639-1705).
Bromeliads are restricted to the New World – in fact, Christopher Columbus on his
second expedition to the Americas in 1493 encountered the most widely known representative
of the family, the pineapple. Initially, interest in the family was fairly restricted
to its edible fruit. However, within the 18th and 19th Centuries various explorers, as for instance Alexander von Humboldt, brought more and more species to Europe.
Urn plants (Aechmea fasciata), friendship plants (Billbergia nutans) or
flaming swords (Vriesea splendens), just to name a few, are now standard commercially
marketed plants throughout the world.
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| Habit, anatomy, and ecology |
Bromeliads vary consideraly in size and appearance, so that a generalizing description is not quite possible.
While a mature, blooming Tillandsia bryoides may be the size of a fingernail,
the funnel rosette of certain Alcantarea species may easily be one meter in diameter.
The inflorescence of Tillandsia grandis may attain a height of 2 m or more.
Most prominently, however, the Andean Puya raimondii, growing at up to 4000 m elevation, forms gigantic inflorescences 10-15 m tall.
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All bromeliads are perennials, i.e., persist for many years. Interestingly, an individual stalk will grow above-ground, mature, set flowers and fruit –
and then degenerate. This entire process may last several years, however.
Rejuvenating or renewal buds, so-called suckers, then resume growth from the base of
the plant forming another shoot (a similar feature as in bananas).
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Most bromeliads grow stout rosettes, actual shoots occurring
only in very few species.
Many species form funnels or urn-shaped central "pools", which serve for accumulating nutrients
and water. These "ecological niches" (biotopes) bear a myriad of tiny animals and insects making
these bromeliads their permanent home. Even certain tropical tree-frogs (Hylidae) and
shrimp-like crustaceans may thrive here, aloft, way up in the trees in the rain-forest.
Dead decaying organisms and animal excretions are trapped and the resulting nutrients become
available to the plants which take up this food through their leaves.
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Bromeliad leaves are parallel-veined, a common feature of
all monocots, usually smooth or spiney-edged. Their appearance often reflects the climatic
features of their environment. Genera from dryer regions of Central and South America as
Hechtia, Dyckia or Puya absorb water through their roots, and deposit
large amounts in their leaves so that some may take on the appearance of a succulent aloe
or century plant.
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The leaves of certain species of Tillandsia from foggy
areas with low total precipitation are often covered with scales, which give the plants a
silvery-gray appearance. These scales (actually trichomes, or scale hairs) is another
characteristic feature of bromeliads.
They serve to substantially increase the leaf surface, which allows condensation of fog,
mist, and air humidity. Like blotting paper, water and nutrients are absorbed directly by
the leaves, bypassing the roots. Scales not only are lining the leaves on the outside,
but even inside the funnel in the water reservoirs. Such species cover the supply of
most of their water and nutritional requirements via the leaf surface so that the roots
mainly serve for attaching the plant to the substrate.
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| Distribution |
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Bromeliads are restricted to the New World, i.e., the
continental Americas. One single species, Pitcairnia feliciana, is native
to West Africa – still a mistery for scientists.
In the North they extend into the US from Florida to East Virginia at about
38° latitude, in the South they reach the southern parts of Argentina and
Chile, down to about 44° latitude.
Some few species from southern Chile have even become naturalized in Europe;
various Fascicularia and Ochagavia species are found in parts of
Irland, England, the Channel Islands (Guernsey), Isle of Scilly, and in Western France.
Species diversity varies considerably within the natural range of distribution,
encompassing 80° of latitude, forming local hotspots, such as Mexico and
Central America, eastern and southern Brasil, and the Andes from Peru, Bolivia,
and Ecuador – the vast Amazon Basin, however, has relatively few bromeliad species.
Their impressive degree of adaptabilty has led bromeliads to become established
in the most diverse environments:
- dry and hot deserts (otherwise mostly devoid of plant growth)
- dry savannas and thornbush vegetation
- tropical-humid lowland rainforest
- cool, montane cloud-forest
- rocky-dry valleys
- even high-elevation grassland (paramo).
In Peru, bromelids are found at elevations of 4000 m or higher with night-time
temperatures often dropping well below freezing. The plants can only survive in such
harsh environments because of concurrent climatic dryness; requiring such special
conditions for their growth precludes outdoor cultivation of these plants in temperate
climates, such as Europe or the US. Among contemporary plant families, and on a
global scale, it is clear that only the orchids show such a vast degree of diversity
and adaptability as to compete with bromeliads.
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What are Bromeliads?
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