Many captivating plants are to be found as miniature counterparts of familiar indoor plants. Almost every plant family has miniature forms, replicas in almost every detail of the larger forms.

Many miniatures occur in nature. Others have occurred as mutations in cultivation. Still others might be called man-made, the result of selection or breeding by dedicated horticulturalists.

Small relatives of the familar rubber tree and fig tree were described in recent Indoor Gardener columns. Some other popular indoor plants that have small forms useful for gardening in limited space are English ivy, grape ivy, nerve plant (Fittonia), peperomia, begonia, African violet, orchid and some ferns.

True miniatures are usually defined as plants less than 6 inches tall, although allowance is made to include plants as tall as 10 inches for some species.

The cultural requirements of miniatures are similar to those of the larger members of the family. Exceptions may arise in the matter of water, humidity or temperature.

As with any plants grown in small pots, miniatures -- grown in containers in scale with their size -- may quickly exhaust the water available in the small amount of soil. Maintenance of high humidity is important to some. For these reasons, it is preferable to set up a special growing area for miniatures rather than scatter them among other plants. Otherwise, the miniatures may be overshadowed, overlooked or fail to receive the care they need.

Your reason for growing miniatures may be simply that you like miniatures of anything, from poodles and dollhouse furniture to tiny flower pots; or it may be that you want to know and grow all the different forms of one plant species that is of special interest to you, such as begonia or African violet. Or it may be the appeal of the sheer fun of showing off the little gems to exclaiming visitors.

Miniatures are the answer to the problem of space limitations. A windowsill garden will accommodate many more miniature African violets than standard size plants, for instance.

Miniatures are ideal for fluorescent light gardens, where space is sometimes at a premium and where it is usually easier to manage plants of uniform size or ones that don't grow too tall.

Many miniatures are perfect for dish gardens. Slow-growing cactus and small succulents can be assembled in a desert landscape effect for use in a dry, sunny location where air circulates freely. Such a garden will retain its proportions for years.

A host of these miniatures grow best in the confined atmosphere of terrariums where humidity is high. Their small size assures that they do not outgrow the space. Some flowering types, such as begonia and sinningia, produce flowers in greater abundance in the protected environment of a terrarium.

If you are a collector of small pots or ceramic containers, miniatures offer a means of enhancing their display.

Some miniatures selected for open or closed terrariums or for areas where high humidity is maintained are:

Begonia prismatocarpa, Begonia 'Robert Schatzer', Sinningia pusilla, Sinningia 'White Sprite', Sinningia 'Tinkerbell', Sinningia 'Doll Baby', Peperomia rubella, Peperomia prostrata, Pereromia 'Pixie', Ficus pumila, Ficus pumila minima.

Some choices for a dish garden are:

Pin cushion cactus, Miniature jade plant, Miniature haworthia, Gasteria lilliputana.

For the windowsill garden choose among miniatures of:

Roses, Geraniums, African violets, Wandering jew, Wax begonias.

Plant hobbyists and other growers in the metropolitan area are constantly propagating some of the choice miniature plants so that plants can be obtained without too much difficulty. A telephone call to some of the following sources with whom I have recently been in touch will answer your questions about available plants:

Potomac Garden Center & Greenery, Potomac, 299-6995; American Plant Food Co., Inc., 5258 River Rd., Bethesda, OL6-3311; The Plant Store, 321 S. Washington, Alexandria, 549-5531; Behnke Nursery, Beltsville, 937-1100; Ryan's Plants & Flowers, Tysons Corner Center, 790-0688.

You also request catalogues from several mail order nurseries. These nurseries carefully package the small plants and ship them at the proper time. Some specialists in small plants are:

Kartuz Greenhouses, 95 Chestnut St., Wilmington, Mass. 01887 (catalog $1).

Logee's Greenhouses, 55 North St., Danielson, Conn. 06239 (catalog $1).

Indoor gardening questions may be sent to Jane Steffey, The Weekly, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Please include your address and telephone number.