What do you need to know about caudiciforms?

What classifies a succulent as a Caudiciform?

Caudiciform, which means ‘like a stem’, is derived from the Latin word caudex, meaning ‘tree trunk’. As the name implies, these plants have something that resembles a stem but looks a bit different than the norm. Specifically, caudiciforms have a caudex, which is an enlarged, bulbous stem or trunk, or a thick set of aboveground roots. In this case, the primary reason for plants to have these iconic “fat” stems is to store water.

Examples of well known caudiciforms from southern Africa

Dioscorea elephantipes – Elephant’s Foot Plant

There are hundreds of examples of caudiciforms, but one of the more famous examples from South Africa is the ‘Elephant’s Foot’ plant or Dioscorea elephantipes. In addition, this species has a uniquely fissured appearance and is popular as a collector’s succulent all over the world.

This species can grow extremely large in nature. Evidently, some specimens have been found that are as big as a car, and this would make them thousands of years old. Legally grown soccer ball size specimens, which are generally 10-15 years old, can be found for sale on the market.

There are approximately 15 species of ‘elephant’s feet’ plant native to South Africa. However, there are only a few species that are popular in cultivation, namely Dioscorea elephantipes, Dioscorea sylvatica and Dioscorea hemicrypta.

Adenium multiflorum – Impala Lily

Adenium multiflorum, or the ‘impala lily’, is an attractive caudiciform plant native to the eastern provinces of South Africa. Notably, it is quite famous for occurring in Kruger National Park. Furthermore, this plant is deciduous and only has leaves during spring and summer. During winter, however, it produces bicolor bright-pink flowers. Additionally, many different flower color morphs have been produced in cultivation, ranging from pure white to red, and even pure black.

Othonna herrei

Othonna herrei is a dwarf shrub succulent species that occurs in the Nama Karoo region. It is one of the most sought after plants in the genus due to its knobbly stem. These protrusions are formed from old leaf bases, which are known as phyllopodia.

Euphorbia

There are many succulent Euphorbia species native to southern Africa that have a caudiciform stem, particularly the ‘medusoid’ speces. Consequently, this feature allows growers to cultivate some of these as attractive ‘bonsai’-shaped plants. Examples of Euphorbia varieties with caudexes include Euphorbia x japonica, Euphorbia bupleurifolia, Euphorbia globosa, Euphorbia gorgonis and Euphorbia stellata.

Examples of well known caudiciforms from around the world

Dorstenia foetida

Eastern Africa hosts Dorstenia foetida, a medium-sized caudiciform succulent. Much like Adenium multiflorum, it is deciduous and will lose its leaves in winter. It produces one of the strangest flowers known to the succulent world, which resembles a starfish. Furthermore, this species is available in a marbled variegated form. Other species include Dorstenia crispa, Dorstenia gigas and Dorstenia contrajerva.

Sinningia

There are several different species of Sinningia. However, few have a true caudex that could qualify them as a caudiciform plant. The most popular species is Sinningia leucotricha, the Brazilian Edelweiss. This plant has white, hairy leaves, and produces bright orange flowers. Another lesser known species is Sinningia bullata, which grows attractive, veined dark green leaves with woolly undersides. Lastly, we have even produced hybrids of these two species, Sinningia bullata x leucotricha.

Other types of caudiciforms

Did you know that there are trees classified as caudiciforms? The famous African Baobab (Adansonia digitata) is not only the largest stem succulent plant on Earth, it is also one of the largest caudiciforms. The Queensland bottle tree (Brachychiton rupestris) from Australia is another famous caudiciform tree.

Some other examples from southern Africa include Cyphostemma, Fockea edulis, Ipomea, Trichodiadema and several Pachypodium species. Caudiciform plants occur all over the world, though. There are a variety of arid areas on our planet, and many of these include their own species of caudiciform. Bursera and Pseudobombax occur in several regions of Mexico, Jatropha originates in the United States, and Stephania heralds from southern Asia. 

Caudiciforms in our collections

What is your favourite caudiciform, or which do you have in your collection? Two favourites for the Living Desert Plants team are Dioscorea elephantipes and Dorstenia foetida.

Written by Harry Lewis, succulent specialist & conservationist