Gesneriads

Whatever is a gesneriad? Almost all individual plants belong to larger plant families. In the case of the African violet whose botanical name is Saintpaulia the larger family is the “Gesneriads” or Gesneriaceae in botanical Latin. Sometimes the relationship is made obvious by readily apparent similarities in the plant. For example, yes, the Florist’s Gloxinia (properly called Sinningia speciosa) is also a gesneriad and bears a substantial outward resemblance to the African violet. There are many more and this outward resemblance is often not nearly so obvious.

The whole gesneriad family has a big following among amateur and commercial growers. There are local plant society’s devoted entirely to growing of the family and many African violet societies include gesneriads in their programs and shows. A large society in the United States with members world-wide is devoted entirely to promotion and study of the family. This society is called The Gesneriad Society. (It was formerly known as the American Gloxinia and Gesneriad Society.) We present a brief introduction to gesneriads here, but, if you are interested in more detail and photos, visit their web site at http://www.gesneriadsociety.org/. The Gesneriad Society is holding its annual Convention and Show in Vancouver this year, June 29-July 3. For more details about this show, see our Coming Events page.

The gesneriad family is very large covering many genera and species and we do not have space for a detailed description of all. They hail from many environments around the world, but most are tropical or semi-tropical. As an introduction we will group and describe the plants by root-type and growth habit and name a few of the more familiar species in the type.

 Fibrous-rooted Gesneriads

A fibrous-rooted plant forms a fairly typical root ball which resembles the branching of a tree that is viewed upside down. African violets and a large number of other gesneriads fall into this category. Among the others is Episcia also known as the “Chocolate Soldier Plant” or “Peacock Plant” which has the added distinction of having stolons which spread the plant similarly to the runners of a strawberry plant. Aeschynanthus (Lipstick Plant), Columnea, and Nematanthus (Goldfish Plant) are other examples of the fibrous-rooted type. These three are commonly grown by hobbyists as basket plants as the majority have a trailing growth habit. Among the most popular and very closely related to African violets are Streptocarpus (Cape Primrose) and its trailing subgenus Streptocarpella.

Tuberous-rooted Gesneriads

A tuber is an enlarged storage area on the root of some plants. People familiar with the common potato will know exactly what a tuber is as will anyone who has grown tuberous begonias. Tuberous plants will go dormant during trying conditions of heat and drought and are reborn from the tuber when the conditions become favourable again. The gesneriad family has a major group of members that are tuberous. This genus is known and Sinningia and it has many species, large and small, low-growing or almost tree-like. Sinningia hail from Central and South America. The so-called Florist Gloxinia is actually a Sinningia, while the plant that is truly called Gloxinia is in the next category below, rhizomatous gesneriads. The only other Gesneriad that produces tubers that is frequently encountered is called Nautilocalyx.

Rhizomatous Gesneriads

A rhizome is a thickened section of plant stem usually found below ground although it can occur above ground. Like a tuber, it is a storage mechanism and rhizomatous plants will go dormant under adverse conditions just as tuberous ones do. Rhizomatous gesneriads include Achimenes which is often grown as an indoor or outdoor basket plants, Smithiantha (Temple Bells) popular as an indoor upright plant, Kohleria, and many more. This is an interesting group of gesneriads because they are so closely related that many intergeneric hybrids are possible.

A few photos of selected gesneriads appear on the right. Please visit our Photo Gallery to see more shots and appreciate the immense variety of this plant family.

The Gesneriad Society devotes more attention to the entire gesneriad family. If you find the gesneriads of interest to you, you should visit their web site: http://www.gesneriadsociety.org/.

Another web site with excellent information and images of gesneriads is the Gesneriad Reference Web maintained by Canadian gesneriad expert Ron Myhr: http://www.gesneriads.ca. You may also want to visit the web site of Brazilian expert Mauro Peixoto: http://www.brazilplants.com/. Many, many gesneriads are native to Brazil.

Some very unusual plants are found among the African violet's Gesneriad relatives. This is Sinningia leucotricha which hails from South America. Would you believe that it is not only a relative of the African violet but it is even closer kin of the popular "Florist's Gloxinia"? The latter is properly called Sinningia speciosa. All Sinn-ingias have tuberous roots.

Petrocosmea minor shown here is another of the gesneriads that like the African violet is fibrous-rooted. It also grows symmetrically, even more so than the African violet.

Very close kin to the African violet but with long strap-like leaves is the Streptocarpus. This is a variety called "Rose-bud". A special article to help you grow Streptocarpus is available this month on the web site. Click here to see the article in PDF format.

There are more photos of gesneriads in our Photo Gallery.

You will need the free Adobe Reader program to view or print these PDF documents. Click here to download Adobe Reader.