The weirdly colorful world of bromeliads

Bromeliads! There are more than 2,000 species and hybrids of them in the United States. Some are mottled, while others are striped, fuzzy, or smooth. They can be miniature or mammoth, and they grow in weird and wonderful colors.

Yet most of us are familiar with only two, the pineapple (Ananas), which Columbus took back with him to Europe, and the airy Spanish moss (Tillandsia), which picturesquely drapes the branches and twigs of many large oaks, pines, and other trees in the South.

Most of those that are grown in the US are epiphytes, or air plants. Yet they are not parasites, but use their root system mainly for anchorage.

Bromeliads, named after Olaf Bromelius, a noted botanist, are among the most extraordinarily interesting plants in the world.

Originally from the rain forests of Brazil and other tropical regions in the Western Hemisphere, where they had to struggle for survival in the jungle, they will still attach themselves to the rough bark and branches of trees or grasp hold of rocks or other plants.

Bromeliads, however, are very adaptable. They can be easily tamed as houseplants or will grow in a small greenhouse. They'll also thrive in small containers filled with hardwood bark or redwood shavings.

Almost any well-drained medium will be satisfactory, such as sphagnum, perlite, or fernroot, if it is laced with leafmold and a touch of soil.

In frost-free areas, such as southern Florida, they'll grow well outdoors without gardeners having to worry about protecting them from the weather.

Bromeliads get their food from the air and from their own decaying leaves and other debris which lodge at their roots. They also get it from elements in the rainwater they catch in a vaselike, water-holding cup which they produce.

This ''cup,'' which also supplies them with their moisture needs, is found inside a flower spike that grows in the center of a rosette. And because of this substantial water-storing capacity, bromeliads can endure drought for prolonged periods of time.

Although they are all quite rugged and few plants can withstand neglect as well as they can, one of the big secrets to growing beautiful bromeliads is to make them comfortable and treat them kindly. But don't overdo it.

Besides a light, well-drained medium, they also prefer moderate fertility. A feeding of liquid fertilizer at half strength or less once a month, and especially when they are about to flower, poured directly into the plant's cup, is sufficient.

Although they can tolerate a wide variation in sunlight and a considerable range in temperatures, bromeliads prefer filtered light, such as is available through the leaves of trees, and the normal room temperature in your home, lowered a few degrees at nighttime.

The plants have an inherited preference for humidity but are quite flexible. If you keep their cups topped with fresh water, they'll furnish their own moisture needs and sustain themselves for considerable periods without attention.

Most growers find it more practical to increase their stock from a ''mother'' plant, which puts out suckers, or offsets - sometimes as many as 15 - rather than from seed. Nature provides for these offsets to be severed and potted to begin their own life.

Because bromeliads are easy to grow and care for, have exquisite foliage - some with striped, banded, and often strikingly colorful leaves - and lovely, long-lasting blooms, they are rapidly becoming among the most exciting and popular plants in the United States.

One of the most fascinating displays of bromeliads anywhere is at the Orchid Jungle, 26715 Southwest 157th Avenue, Miami. The Orchid Jungle, which also has the world's largest outside orchid garden, is open daily from 8:30 a.m. to 5:30 p.m.

To learn more about bromeliads as a beginner, you might want to obtain a book , entitled ''Bromeliads for Modern Living,'' by Dr. Louis Wilson, Merchants Publishing Company, in paperback. For more advanced bromeliad fanciers, there is ''Bromeliads,'' by Victoria Padilla, Crown Publishers. Check with a local brookstore for the current price.