As expressive as paintings and as appealing as antiques, houseplants bring life to every room. They're also Martha's secret to decorating her Bedford, NY, home with a flourish.

Martha holds a potted Agave victoriaereginae, one of many sun-loving succulents in her greenhouse.

At one end of her multiuse Brown Room, Martha gathers assorted fancy-leaf begonias to give each guest a different perspective on the rich diversity of these rhizomatous hybrids. From left are 'Emerald Lacewing,' 'Hocking Wink,' 'Caravan,' 'River Nile,' Begonia soli-mutata, 'Othello,' 'Hocking Wink,' 'Heirloom,' and 'Emerald Lacewing.' Open shelves present a study in man-made diversity: Martha's antique glassware. Mainly American, the pieces are intermingled with a few European examples. Some of the compotes, tumblers, vases, jars, and other pieces date to the 18th century. Their crystalline sparkle sets off the begonias' velvety foliage, while faux-bois doors and richly veined marble tabletops join in the play of pattern on pattern.

"I don't paint window frames white anymore," Martha says, "because the bright trim interrupts the view outside." Daylight dapples the leaves of a bonsai Japanese maple, Acer palmatum, atop a Norwegian rococo table. The mirror above it has a 19th-century American gilded frame. One of Martha's French bulldogs, Sharkey, stands near Georgian-style wing chairs upholstered in a Fortuny cotton.

A tall pair of schefflera (Brassaia actinophylla), or umbrella trees, flourish in the Green Room. Palmettes, flowers, and fruits embellish a Swedish neoclassical wall clock. The marble-and-wood pedestal table underneath it, a gift from Martha's daughter, Alexis, supports a cluster of gesneriads, African violet cousins that prefer indirect illumination.

Budding Chirita 'Aiko,' red-flowered Columnea 'Boehme' and 'Firebird,' and the moss Selaginella kraussiana grow in pots made by Guy Wolff, who stamps each with "Cantitoe" and the year it is thrown. Martha buys silver-plate saucers for a few dollars each at tag sales.

Flanking the fireplace, Greek Revival stone columns furnish pedestals for stately jade plants (Crassula ovata). Twin Irish Georgian sofas face each other under an Austrian giltwood chandelier, which is reflected in an early-19th-century Swedish cornucopia mirror.

Martha uses antique cast-iron stands in the Bird Room to carry, from left, variegated ivy, Hedera helix cv; maidenhair fern, Adiantum pedatum; and rainbow moss, Selaginella uncinata. Bartok the cat sits below "Canary (2)," part of a set of gravures by contemporary artist Carsten Holler.

Succulents and cacti are kept on an American Empire mahogany table with paw feet. From left are old man cacti, a paddle plant, dyckia, a baseball plant, a notocactus, a tall variegated prickly pear (center), sand rose, chocolate echeveria, a star cactus, a golden star cactus, a dune aloe, a red bearded Irishman, lipstick echeveria, and an uebelmannia.

In front of an American Empire gilded pier glass, the orchid hybrid Colmanara catatante 'Pacific Sun Spots' produces vivid spires. "Orchids are much easier to maintain than I thought before I started growing them," Martha says. The Wolff orchid pot has holes for root ventilation. Stick-on pads under a saucer protect the finish on the tea table, which stands beside a damaskupholstered settee in the style of Duncan Phyfe.

Paphiopedilum orchids grace Martha's bedside table, next to a lampshade that she designed for a Chinese crackleware base. Etched mirrored sconces catch light overhead. On the 18th-century mahogany four-poster, a subtly patterned Japanese linen covers the pin-tucked duvet and also lines the canopy. The bed's boldly scalloped gabardine pelmet and skirt contrast with the intricate embroidery on antique linens.