The Gesneriad family contains some of the most decorative and widely grown of the tropical plants. Although the majority of the family will be unfamiliar to most people, even to accomplished horticulturists, virtually everyone knows the African Violet (Saintpaulia hybrids), and the common Gloxinia (Sinningia speciosa hybrids) of florists shops and garden centers. The Lipstick Plant (various species of Aeschynanthus) is also widely grown, and it is not uncommon to see Goldfish Plants (usually Nematanthus species and hybrids) for sale in supermarkets and garden centers.
These most visible members of the family barely scratch the surface. There are literally hundreds of others, many at least as worthy of consideration by the apartment grower or the commercial specialist. Some are large and spectacular, as certain species of Columnea, producing ten foot (three meter) trailing stems covered with bright flowers. Others are diminutive and delicate, like Sinningia pusilla, growing comfortably in a thimble-sized pot, with perfect tiny flowers held high above the tiny leaves.
Not all are grown for their flowers. For example, Episcia species and hybrids (sometimes called "Flame Violets" or "Chocolate Soldiers") often have very colorful and patterned foliage, ranging from a combination of pale pink, white and green through dark red and chocolate brown to brilliant emerald green. The flowers of Episcias are usually bright reddish orange, sometimes pink, lavender or yellow. The red flowers clash with the delicate pink leaf colors of some of the varieties, so growers take off the buds before they open these are truly foliage plants!
Some of the gesneriads grow naturally in moderately moist and shady conditions, with steady warmth. They are often comfortable in typical household conditions, and are good candidates for the new grower. Others grow at high altitudes, in the constant presence of cool mists, and require more specialized and constantly moist conditions. Still others grow on rocky slopes or cliffs, or high up in the rainforest canopy in small deposits of moss or leaf mold. They are adapted to occasional drought, and a grower must take care not to overwater.
All in all, the gesneriads are an interesting, sometimes fascinating, plant family. Many can be grown easily in the average home, and regardless of a growers conditions or expertise, there is always a very desirable plant that is just tricky enough to provide a challenge, but just easy enough to be worth trying. Its a true recipe for addiction.
Where do Gesneriads come from?
The Gesneriaceae are widely distributed
throughout the tropics of the world, with a number of species growing in temperate
climates, especially at high altitudes in mountainous regions of Asia, Europe and South
America. Among the more common varieties, Saintpaulia (African Violets) come from
east Africa, especially Tanzania and Kenya. The Lipstick Plants (Aeschynanthus) are
native to the Malaysian archipelago and nearby locations in south Asia. Sinningia
species, including the Florist Gloxinia, come from Brazil, as does the Goldfish Plant (Nematanthus).
The only Gesneriads growing in Europe are some species of Ramonda, semi-hardy
alpines from the mountains in the south. These can be grown outside as far north as
Scotland. A few relatively obscure species grow in Australia and New Zealand, and none are
known from North America.
How Are Gesneriads Classified?
Gesneriads are grouped in several ways, depending on the inclination of the classifier or the purpose of the grouping.
Botanical taxonomy makes a fundamental distinction between "Old World" Gesneriads, from Asia, Africa, Europe and Australia, and those from the "New World", essentially South and Central America. The former are said to belong to the sub-family Cyrtandroideae, the latter to the sub-family Gesnerioideae. The distinction is not simply arbitrary, based on geography, but flows from some of the fundamental characteristics of the Gesneriads that grow in these areas.
As with all plants (and animals, for that matter) each of these sub-families are further divided into Tribes and Genera and Species. A fairly detailed description of the botanical taxonomy of the family may be found here in the article Gesneriaceae, by Brian Morley.
Gesneriads are also sometimes classified according to the types of roots they have. Most members of the family have "fibrous" roots, the simple root pattern most often seen in common plants. In fact, all of the Old World members of the family have fibrous roots, as do most of those from the New World.
However, a number of interesting and beautiful species from Central and South America have roots that are adapted for survival through periods of dormancy in response to climate conditions such as drought or cold.
The tuberous Gesneriads usually have a single fleshy tuber, often reminiscent of those produced by some types of Begonias, but sometimes more like a potato. When a dry or cold season comes, the foliage will die down but the tuber will live on. When good weather returns, new growth will start up from the tuber.
Sometimes, tubers will grow at the surface of the soil, with much of the tuber showing above the ground. These types of tuber can grow very large, providing an odd and interesting sight the tuber can seem to be more substantial than the foliage growth above it!
Almost all of the tuberous Gesneriads are in the Sinningia genus, which is a highly diverse group of plants. Size of the Sinningias ranges from tiny (S. pusilla can grow in a thimble, and has a tuber the size of a pea) to the substantial (S. macropoda can spread to two or three feet, with a tuber as much as 12" (30 cm) across). Habitat of the Sinningias is also quite diverse, with some species growing in cracks in solid rock walls, and others in moist moss in the deepest tropical forests.
The rhizomatous Gesneriads have underground stems, with leaves that have been modified into closely packed scales around the central stem. In some cases, these scaly rhizomes will grow very long, wrapping around the inside of the pot. In nature, they would have grown horizontally away from the center of the plant. In other cases, each plant produces many small scaly rhizomes, clustered underground at the base of the plant. As with tuberous Gesneriads, the foliage dies down in response to weather conditions, and the rhizomes resprout when conditions become more hospitable.
There are a number of fairly closely related genera which produce rhizomatous roots. Among the more commonly seen are Achimenes, attractive basket plants with origins in Central America, and Kohleria, from Central and South America, with spectacularly bright and spotted flowers.
Are There Gesneriad Relatives?
Closely related to the Gesneriads is the large foxglove family, the Scrophulariaceae. Many common garden ornamentals come from this group, including foxglove (Digitalis), snapdragons (Antirrhinum), monkey flower (Mimulus), Veronica, Calceolaria and Pentstemon.
Also closely related is the catalpa family, the Bignoniaceae. Included in this group is Incarvillea, a common garden perennial often sold as the Hardy Gloxinia. Its not really a Gloxinia, but it is a relative.
Because they are mainly tropical, often beautiful and frequently exotic, people sometimes wonder if the gesneriads are a kind of orchid. Theyre not closely related, but there are some similarities.
Both orchids and gesneriads appear to be relatively recently evolved, and to be in the process of rapid differentiation. In both groups, specific flower shapes seem to have developed as a result of co-evolution with pollinators, with some very specific pairings between plant and pollinator species. Both also make use of a wide variety of pollinators, including hummingbirds, moths, butterflies, bees, wasps, ants and bats. It is perhaps because of the close relationship between pollinators and plants that both orchids and gesneriads are so popular as ornamentals the pollinator relationships result in a wide diversity of large and colorful flowers, which humans, as well as pollinators, find attractive.
What Are Some Examples of Interesting Gesneriads?
Columnea 'Early Bird'
Aeschynanthus 'Big Apple'
Sinningia 'Wood Nymph'
There are many interesting members of the Gesneriad family, almost 1000 of which are illustrated on this website. Some are kind of obscure, and a few are more interesting than attractive. But there certainly is lots of diversity.
For instance, the Streptocarpus genus is becoming increasingly popular as a relatively easy-to-grow houseplant, especially where summer temperatures do not get too hot and humid. S. Sandra is a particularly beautiful hybrid, popular in Britain and recently available in North America.
Among the trailing plants, the Columneas can be spectacularly beautiful, and are often not difficult to grow. An excellent example is the old hybrid C. Early Bird, still available from many sources. Although the relatively common "Lipstick Plant" (Aeschynanthus species) is attractive and easy to grow, other members of this genus also make good basket plants. A. Big Apple is an example of a recent hybrid that has achieved great popularity.
Many growers are captivated by the Sinningia genus, and it is in fact truly interesting. The spectacular "Florist Gloxinia", available at every florists and nursery and even many supermarkets, is the most familiar example, but there are others which will provide much more pleasure for someone wanting to grow and maintain interesting plants at home. The miniature Sinningias are very popular -- its easy to see why when you discover a little plant like the micro-miniature S. 'Wood Nymph'. Among the larger-growing species, the recently introduced S. conspicua has become very popular.
Many gesneriads are grown for attractive foliage, often patterned and marked in contrasting colors. The Episcia group provides most of the widely grown foliage plants. Perhaps the most spectacular is E. Cleopatra and its look-alike relatives. Cleopatra, with its pale pink, white and green markings, is not particularly easy to grow, as it requires warm temperatures, constant moisture and high humidity. But thousands of people do, and successfully!
Among the more recently introduced gesneriads are the Chiritas, most of which are native to China. Some, like Chirita sinensis, are grown for their attractive leathery silver foliage, but others, like C. Aiko, are grown for beautiful lavender, white or yellow flowers.
Browse the site, and youll see many other
beautiful gesneriads. The "Best of the Site" page can be a good starting
point, as can the Articles and Tours.
How Do I Learn More About Gesneriads (And Where Can I Get Some)?
The best strategy for learning about gesneriads is to join a gesneriad club, many of which are affiliated with the American Gloxinia and Gesneriad Society. The Gesneriad Society is an excellent place to start, because of the informative publication (Gesneriads), the extensive seed listing accessible only by members, and the information on culture and local organizations that can be obtained.
There are many sources of plants, particularly in North America, and a number of listings of these can be found on the websites of the Gesneriad Society and the African Violet Society. Also included on these sites is information about membership. Check out the Links Page for direct access to other online resources.