For gardeners raised on seed catalogues lavish enough for the coffee table, specialty garden cat alogues recall mimeographed PTA notices. The text is sometimes strange, and typographical errors are frequent. The prices are low. But there are curious warnings, such as "delivery is made from next fresh harvest after receipt of order and a delay of several months may occur before seeds are forwarded. In the event of crop failure orders are held until next available harvest unless a prior cancellation is received."

But as a source for rare or unusual plants, it is hard to beat The Banana Tree catalogue, published in Easton, Pa. (715 Northampton St.). It offers corms (tuber-like bulbs) of 11 varieties of bananas, from one called Apple ("the fig leaf in the Garden of Eden") to Jamaican Red with a growing time of only 23 months. The list also includes Lacatan (the familiar Chiquita brand), which is only 8 feet tall, and Hua Moa, which means "chicken egg" and bears a fruit that resembles a melon, "great tasting [when] baked with cinnamon and brown sugar." The price range is from $4.25 to $6.95 per corm.

The Banana Tree sells exotica usually seen in botanical gardens: climbers such as African wisteria, Taiwan hibiscus that "changes color from white in morning to pink-red at late noon," palms of a bewildering variety, and strange plants such as the Australian "grass tree," which is "a rigid black trunk topped with reed-like grass." Among its herbs are the snake palm (Amorphophallus Rivieri) used in Indian cooking and peacock ginger from Burma ("a pink flower every 24 hours").

Seeds of fruit trees offered include those of the macadamia nut ("although 3 months may be needed to germinate, it is worth it"), pistachio chinensis ("easy to grow" and "likes arid conditions"), miracle fruit or synsepalum dulcificum (its berries "cause food to take on a sweet taste up to 2 hours after eating"), date palm ("a true date-bearing plam" that "germinates in 65-80 days) and malabar chestnut ("large seeds edible raw or toasted").

The Banana Tree also sells the seeds of 16 types of Chinese vegetables.

No less than 121 herbs, from alecost to woodruff, are listed in the 1983 seed catalogue of Earthworks Greenhouse & Herb Garden, an herb nursery in Arlington. (923 N. Ivy St.). Of special interest are hard-to-find Balm of Gilead (with a "rare, rich fragrance"), Good King Henry ("a tasty pot herb much neglected in the U.S.") and three varieties of the famous lavenders of Provence.

Founder-owner Thomas De Baggio headlines two plants that he says are his discoveries. The first is Narrow Leaf rosemary -- "more cold hardy than many varieties" and with "a strong rosemary aroma, making it an excellent variety for the culinary garden." The second is Two Seasons lavender -- "a hardy variety which blooms twice a year, pressenting double the number of blooms obtained from other, single-season varieties."

Earthworks offers, "for the first time in America," a new French hybrid asparagus, called Larac, that "out-produces all other varieties." The price for 16 pots of one-year-old plants is $18.95. Another innovation is vegetable plants in 2 1/4-inch individual pots. Pots permit better root growth and in packs of four are priced the same as last year: $1.39.

Raymond Saufroy worked as a chef in New York before he moved to West Danville, Vt., to run his nursery, Le Jardin du Gourmet. In his 1983-84 catalogue he features items few, if any, nurseries offer.

Rocambole, known as Spanish garlic or Spanish shallots, is "a kind of garlic grown from seeds the size and shape of apple pits. Different and flavorful, delicate, unlike elephant garlic that has no taste or flavor. I finally acquired a few with great difficulty." A pack of seeds is $1.25.

Raddichio (Cicoria rossa di Verona) is "a compact red lettuce with white ribs" and "the rage of New York restaurants. Imported fresh, by air, from Italy." The price is 95 cents a packet.

Mache, or corn salad, has "small round or oval leaves" and is also "the rage in the best NYC restaurants [and in Europe]." The price is 95 cents a packet.

Le Jardin du Gourmet sells three kinds of shallots -- regular, frogs' legs and elongated. It has also pioneered the 20-cent seed packet, containing only a small number of seeds, such as five for pumpkins, 10 for cucumbers.

There are 64 herbs offered. For $1 the firm sends eight sample pockets of herb seeds, the catalogue, instructions and recipes.