Choose a country to see content specific to your location

Skip to main content

Exotic Succulents | Asclepiads

Going.Local
Published on February 27th 2020
40
A close up of a doughnut
Spanning the Arabian Peninsula to the forests of Central and Southern Africa, a group of plants have emerged that rival orchids in their diversity of blooms (1). The subfamily, known as Asclepiadoideae or milkweed/carrion plants, is well known for their odour but few know of their true brilliance.
A close up of a flower
Huernia humilis thudichumi
We will be kicking off this series with a closer look at the myths surrounding the stem succulent contingent of this massive group of 3000 species and providing some guidelines as to how to select and grow your own.

MYTH: They all smell horrid!

Surprisingly, this is not true as the odour differs significantly between species. The ability to release a carrion smell is known as scent mimicry, a trait some share with several orchids as well as the world-renowned corpse flower (Amorphophallus titanum).
A close up of a Amorphophallus titanum flower

Titan Arum

Amorphophallus titanum

The misconception is perpetuated by the strong smell of the most commercially available species i.e. Stapelia gigantea, S. grandiflora, S. leedernziae and Orbea variegata. Species such as Stapelia flavopurpurea give off a light sweet honey smell whilst several Huernia species (H. zebrina) can be covered in blooms and produce no discernable sent (2).
A close up of a stuffed animal
Most common commercial varieties are Stapelia grandiflora and S. gigantea.

MYTH: They attract only flies!

Carrion flowers attract a staggering array of wildlife. The most striking include the African Monarch butterfly and Cape dwarf chameleon (3). The latter may follow the flies, but the former follows the scent of the flowers. They also play host to terrestrial frogs, geckos and lizards.
A close up of food
Carrion flowers attract a vast array of wildlife including the African Monarch butterflies, dragonflies and chameleons.

I WANT ONE, but which one?

You will soon find that stem succulents within this subfamily can include Duvalia, Edithcolea, Echidnopsis, Hoodia, Huernia, Orbea, Orbeopsis, Piaranthus, Stapelia, Tridentea and many more. Where do you start a collection and how do you choose?
Trailing species | If you find yourself enthralled by the hanging basket craze then you’ll find almost all the species form trailing clumps. You can choose between any Echidnopsis, Edithcolea, Orbea or Stapelia and find the blooms in your favourite colour.
Easy to Grow | The easiest to grow would be either an Orbea or Stapelia. The commercially ubiquitous species are normally of the “leave them and they will flourish” variety. If you're starting out then it is best to avoid the difficult species such as Edithcolea grandis or South American Caralluma species (no matter how drop-dead gorgeous those blooms are).
Flamboyant flowers | This is largely dependent on your individual taste. If you like moving filamentous parts on your flowers then why not start with Orbea doldii? If you like large blooms en masse then you can always opt for a classical Stapelia grandiflora or for the more advanced a Tridentea gemmiflora. Then there are the striking flowers of Orbea hardyi that combines both a trailing succulent with striking flowers.
A bunch of different types of food
Blooms vary considerably. Shown above clockwise: Orbea cooperi, Echidnopsis daimanniana, Duvalia caespitosa and Huernia.

WHERE DO I BUY THEM

IN SA! Lucky for you there is a comprehensive layout of all the shops that stock succulents in the article link below.
International? No problem, then you can join your local Asclepiadoideae club or contact KAMBROO/SHEILAM nurseries (links in the article above), both ship internationally.

HOW TO KEEP THEM ALIVE

Stick to origin | Do yourself a favour and Google the name or pop it into the comments below and get the natural habitat information. Most of these species go dormant in winter and will not tolerate freezing. Being dormant also means, like bulbs, they require almost no water during these months. Some species are trickier and will require both heat and a nice soaking to flower (this is the exception).
Good resources | Asclepiadaceae.
When in doubt | Water once a week in summer (by soaking the pot and letting it drain) and once a month in winter. If you planted your succulent in compost or pure potting soil then no amount of water advise will help, so keep the next tip in mind.
Start out with the right soil | They grow in sand and gravel. Never, ever think you have added too much sand. The best mix is 50% sand, 50% potting soil (NO COMPOST). If you add perlite or 1-3mm diameter pebbles then it allows for better root formation and growth. The roots need air. This is also the reason for keeping them in ceramic, not plastic. All species are prone to fungal infections, so wait till the soil dries out before watering.
Then sit back and enjoy the blooms!
A close up of a fruit
Duvalia caespitosa

Keen to learn more about these fascinating plants? Dig into their plant profiles below:

Bibliography
1 | Albers, F. & Meve, U. (2002). Illustrated Handbook of Succulent Plants: Asclepiadaceae: Asclepiadaceae, Volume 5. Albers, F. & Meye, U., (ed.), Springer Science & Business Media.
2 | Dimmitt, M. Stapelia flavopurpurea: A sweet starfish flower.” Growing Succulents in the Desert Column August 2010.
3 | Van Jaarsveld, E. (2013). Attracting wildlife to your garden. Gordon, G., (ed.), Waterwise Gardening in South Africa and Namibia. Penguin Random House SA: 23-24.