All about that base

The Puff Adder – a 70-metre wooden structure that slithers through oaks and blue gum trees next to the stream – now plays host to a selection of very rare caudex succulents. Master Botanist Ernst van Jaarsveld explains that caudiciform plants are characterised by a swollen stem base.

These unique plants are all from South Africa, mostly from the Bosveld area, and include 11 different families.

What does a granadilla and a sesame plant have in common?

Succulents store water in their leaves or stems, and are adapted to survive dry periods. Sometimes the fleshy base comprise a combination of root and stem. Caudiciform plants occur in many plant families such as granadillas, oleanders, stonecrops, yams, grapes or the sesame family.

Chomp chomp

Herbivores find those plants with a succulent stem base especially irresistible. Because of this vulnerability, many caudiciform plants have developed smart ways to avoid predation. These can include poisons or bitter sap, or camouflage. So the elephant’s foot looks like a tortoise shell and is well camouflaged among the rocky outcrops of the Namaqualand and Eastern Cape. The impala lily is extremely toxic to herbivores.

The largest of all caudiforms is the baobab tree. Surprisingly, most parts of the tree are edible. The survival trick is that – once the elephants have feasted – its thick bark has the ability to heal with remarkable speed.

Many of the plants currently on display in the Puff Adder were collected by Ernst on a recent bakkie expedition all through South Africa. He was accompanied by Chengy and Xing Quan from the Beijing Botanical Garden and the Bejing Botanical Garden of the Academy of Science.

Grow your own

Because of their ornamental value (architectural stems or beautiful flowers) caudiciform succulents are widely grown. Since they originate in hot, subtropical parts, they flourish in containers in sandy, well-drained soil.

Example: koba is a beautifully thickset, squat little tree from the Namib. It reaches a small tree size and when planted in a well-drained spot in frost-free areas, will also do well in gardens.

Here are some of the rare plants we have on display. (Don’t miss the much-admired halfmens and koedoelelie.)

• Yam family (Dioscoreaceae)

Elephant’s foot (Dioscorea elephantipes)

• Cabbage tree family (Araliaceae)

Mountain cabbage tree (Cussonia paniculata var. sinuata)

Cabbage tree (Cussonia spicata)

• Pumpkin family (Cuccurbitaceae)

Cape bryony (Kedrostis nana)

• Granadilla family (Passifloraceae)

Sesemieboom (Sesamothamnus lugardiae)

Doring-bobbejaangif (Adenia spinosa) (x2)

Blou-bobbejaangif (Adenia glauca)

Groen-olifantsvoet (Adenia fruticosa)

• Oleander family (Apocynaceae)

Halfmens (Pachypodium namaquanum)

Koedoelelie (Pachypodium saundersiae)

Bergkambro, dikvoet (Pachypodium succulentum)

Bobbejaankos (Pachypodium bispinosum)

Impalalelie, Impala lily (Adenium multiflorum)

Kambro (Fockea edulis)

• Stonecrop family (Crassulaceae)

Botterboom (Tylecodon paniculatus)

• Aloe family (Aloaceae)

Baardskeerdersbos-aalwyn (Aloe juddii)

• Grape family (Vitaceae)

Droog-my-keel (Cyphostemma cirrhosum)

Koba (Cyphostemma juttae)

• Sasamy family (Pedaliaceae)

Sandkambro (Pterodiscus speciosus)

Meerkatklokkies (Pterodiscus ngamicus)

Meerkatklokkies (Pterodiscus cinnabarinus)

Meerkatklokkies (Pterodiscus aurantiacus)

• Myrrh family (Burseraceae)

Kanniedood (Commiphora glandulosa)

Vervelboom (Commiphora africana)

• Mesemb family (Mesembryanthemaceae)

Donkievygie (Mestoklema tuberosum)