Mesembryanthemums – AKA Aizoaceae

South African Succulents

This family of succulents is found almost exclusively in the southern tip of Africa, where conditions are harsh, rainfall is minimal, and the weather is generally quite warm. All of the cute little succulents in the family Aizoaceae are typically referred to as “mesembs” even though only some are members of the Mesembryanthemaceae genera.  Mesembs include the ever-popular “living stones” or butt plants, aka Lithops, as well as split rocks, ice plants, flowering stones, and a range of other creative names for these small, rock-dwelling plants. There are 146 genera that fall into Aizoaceae, making it quite a massive succulent family! 

Full of Misconceptions 

Unfortunately for our mesmerizing mesembs, they are a group of succulents that most commonly get poor care information, misinformation, or are harder for novice growers to understand their care requirements. The natural environment these hail from is one that is highly seasonal and as such, these plants have evolved cleverly to their unique and challenging conditions. In the wild, many are found only in specific sites, which is why some species or cultivars are labeled by letters and numbers as a way of designating the original seed or specimen collection location. They often grow in mounds of rocks of varying composition, such as limestone, shale, or quartz, and have roots that are adapted to tiny amounts of organic material. 

When grown in cultivation, many novice growers plant them in material that is too rich, and then water far too much or far too little. Understanding when and how much to water is not as straightforward as some other succulent and cacti species, due in large parts to how they have adapted to their harsh natural conditions. In cultivation, the attempt to have them grow perfectly and look “good” year-round is often what leads to their doom. 

Location in the wild

Aizoaceae are found naturally in the southwestern areas of Africa, ranging from Angola down to the southern Cape, as well as east into Botswana and Zimbabwe. There are a handful of genera that exist up around the Mediterranean sea, Madagascar, Yemen, and out into Australia, New Zealand, and their surrounding islands. In common horticulture in the US, at least, these are somewhat more obscure plants not typically available, with the exception of Lampranthus, which is a common xeric landscape plant. 

The most popular and sought after genera of mesembs are generally lithops, conophytum, and/or pleiospilos, with Braunsia maximiliani being quite popular as well. Nearly all of these are found in South Africa, with a handful of (less common) species ranging up into Namibia and surrounding countries.  

 

South Africa

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Aloinopsis

The genus “Aloinopsis” is part of a general grouping referenced as “Rough-leaved Mesembs” in the book Mesembs of the World, and it’s an appropriate grouping. With 14 species, this genus has a leaf appearance for everyone, but they all share several distinct characteristics. Notably, the roots are quite thick and fleshy, with several having distinct tubers or a large central taproot, as with Aloinopsis schooneesii. They grow in small rosette-shaped clusters, with textured leaves that are egg or spoon shaped. They all have similar shaped blooms, with varying colors – some enthusiasts have even selectively bred for brilliant pops of deep red or orange, but most common colors are yellow, orange, pink, and/or striped blossoms. They bloom mostly from late winter to early spring, and flowers open in the afternoon and close by sun down. 

Care of Aloinopsis

Part of why I love these is how easy they are. They’re quite cold hardy, and some enthusiasts have grown them in conditions that see the occasional dusting of snow! How cold hardy they are depends on the species, although nearly all should be able to tolerate temperatures down to freezing as long as their roots are kept dry. Use a well-draining, gritty soil mixture; I use 50/50 succulent soil to pumice or perlite to ensure that soil is airy and fast draining. They require very little water, along with plenty of bright light. With inadequate light, flowers will not open during their usual time in the afternoon, and this can be a helpful gauge in winter to see if your lighting conditions are adequate. I am currently growing 3 species of Aloinopsis in-ground in a rock garden, with profuse blooming and growth clearly noticeable from the specimens in-ground the longest. 

aloinopsis malherbei

Aloinopsis malherbei

Easy to cultivate and profusely blooming rough leaved mesemb, cold hardy and tolerant of beginner mistakes. 

In Cultivation

One of the more commonly available Aloinopsis species available, Aloinopsis malherbei is also known as the “Giant Jewel Plant”. To be honest, I’m not sure why, as they’re not particularly larger than other mesembs, but that’s the name. 

They thrive in very bright conditions, and should be planted somewhere with nearly full sun, shaded only during the hottest part of the day. They tolerate a very wide range of soils and growing conditions, but for a robust plant, they need plenty of ventilation and a nice, porous soil mix, preferably in a relatively shallow pot. They are cold hardy to the low 30s, and can even tolerate a light frost so long as they are kept dry. They can be grown outdoors, in-ground, in zones 9b to 12, and we have a slope where I have several of these planted (see photo to the left). I keep them moderately weeded, but the smaller plants are hard to eradicate, and I expect the dry heat of summer to kill off anything surviving past spring. 

The more challenging aspect of their care is balancing water needs, particularly during cold and rainy seasons. They are typically winter growers, but should be kept dry when it is cold out, making the balance a challenge for most in the Northern hemisphere. They are prone to rot if they are left too wet for too long, and high ambient humidity can have a similarly detrimental effect. When kept somewhere sunny, well-draining, and well-ventilated, they don’t typically suffer from pests aside from mealybug. 

Most information indicates that they should be sheltered from high heat, which will not be possible for my rock garden mesembs. Check back this fall to see how my in-ground plants fare with our 100F+ heat waves! 

 

Aloinopsis schooneesii

Aloinopsis schooneesii 

Has tiny, pebble-shaped leaves that are deceptively small when compared to the absolutely massive tap root. Generally, the taproot is only slightly smaller than the visible leaves, which can give an indication of just how thick the root is. This thick tap root enables the plant to be extremely drought-tolerant, although it does present challenges for potting. They need a deep pot to accomodate the tap root, and the typical porous potting mix as well. 

In Cultivation

Easy to grow and spreads slowly into a mat-like shape. The little nubby leaves actually grow in vague rosette shapes, although it is often hard to spot. They are winter growers and bloomers, with cute daisy-like blooms that have a thin stripe down the middle of each petal. Flowers will only open if provided with adequate sunlight, and may not open at all on cloudy days. Due to the thick tap root, these make interesting psuedo-bonsai plants, and can be potted up and their tap root slowly exposed to create an alien-like tree. 

Blushes a dark reddish brown in summer if exposed to too much sun, but should be kept with at least half sun – full shade will cause stretching and eventually rot. Water sparingly, especially during summer when they are typically dormant. Due to being quite opportunistic, these may continue growing through summer, but a dormancy period during the hottest months is more typical. 

Can be fertilized mid way through their growing period with a 1/2 strength balanced fertilizer, although this typically isn’t needed. 

aloinopsis schooneesii
Aloinopsis rubriolineata

Aloinopsis rubrolineata (maybe)

Acquired as an unlabeled Aloinopsis, once this bloomed, identification was possible. More robust growth and additional blooms that open up more fully would help identify this specimen more effectively. It was suggested as possibly rosulata, but as that species is even less common, I lean towards rubrolineata, particularly with the leaf shape. Compared to online photos of the species, this one is much smaller in size considering that it is blooming already, but this may be due more to transplant stress and acclimatization rather than being a different species. 

In Cultivation

More finicky than the commonly available aloinopsis species, these have a large tap root similar to schooneesii, but not quite as thick. Extremely cold hardy, with reports of plants surviving through lows of 10F not uncommon so long as plants are kept dry. 

Should be protected from extreme heat/sun in summer, when it is dormant, but it is otherwise similar in requirements to other Aloinopsis. 

Aloinopsis luckhoffii

Aloinopsis luckhoffii 

Another relatively common Aloinopsis as far as species go, due in part to how easy they are to care for. Fairly cold hardy, with some enthusiasts reporting plants that survive temperatures down to 10F and blooming not long after. Mimicking this success as a novice keeper can be quite challenging, however, and if you are new to these plants it is best to protect them from temperatures below freezing. This also prevents unsightly scarring of the leaf tissue. 

In Cultivation

As with other Aloinopsis, use well-draining potting soil, preferably with some gritty pumice or perlite to keep it airy. They need excellent ventilation to thrive, and should be outdoors whenever weather conditions accomodate them. Water sparingly in winter, and little to not at all in summer (depending on your location), as they also go somewhat dormant during the hottest months. 

They will “melt” if exposed to too much sun during the heat of summer, and should be given at least partial shade suring the hottest months. Can be prone to mealybug, particularly if kept in humid conditions or in a greenhouse with poor ventilation. 

Cheiridopsis

This is a large genus of about 100 flowering succulents, with their latin name originating from the greek word “cheiris”, which means sleeve. 

Why sleeve, I’m not sure, except perhaps the way new leaves seem to emerge like little finger growths from within the middle of the old leaves. It’s disconcerting and looks vaguely obscene, depending on the species. 

Most Cheiridopsis have a blue/gray leaf body, and leaves of varying thicknesses. Some are big and thick and fleshy, others have slender tubers that strongly resemble a common ice plant. They all generally make large, showy blooms that are most commonly yellow and white, with a few species producing pink blooms. 

Care of Cheiridopsis

As with most mesembs, these are extremely easy to care for. Keep in bright light, preferably a few hours of direct morning sunlight with shade during the hottest parts of the afternoon. 

These, as with most mesembs, generally go dormant during the hottest part of the summer, and when they wake up each autumn they begin actively growing with new leaf divisions. During winter months is when you can expect the large, showy flowers to appear, and they enjoy regular watering. If temperatures are going to be fairly cold (night time temps below 40F), they should be kept dry, but warmer than that and they enjoy regular moisture. Unlike lithops, they don’t really absorb older leaves immediately, so the moisture is appreciated as they produce new leaves and blooms. 

Cheiridopsis denticulata

Cheiridopsis denticulata

A long-toothed mesemb that looks like an icy, slate-gray ice plant. Many Cheiridopsis look very similar, in part because what makes them a cheiridopsis is the leaf similarity…

What nearly all Cheiridopsis share with this species is the proclivity to produce large, sunshine-yellow blooms, occasionally ranging to a more white color. C. denticulata is one of the more common species, although they aren’t exactly commonly available at most nurseries. 

The species is listed as Not Threatened, although finding domestic or captive produced plants and seed is still preferable. They originate from Namaqualand, where they grow in small stands almost entirely made of only their species.

Care in Cultivation 

Easy to grow once you get their soil dialed in, they prefer a gritty, sandy mix that is well draining. As with many mesembs, they go dormant in the hot summer months, developing more compact new leaf growth and allowing the longer leaves to shrivel and form a protective sheath at the base. 

Water well in fall through winter when they are actively growing, but keep water minimal in summer – a light misting to help them get through the heat of summer months should be all they need. 

Cheiridopsis namaquensis

Cheiridopsis namaquensis

Smaller in leaf-body size, these are a mat-forming species that stays relatively small. As with other species in this genus, it is most actively growing in winter, flowering profusely in early spring. 

These are also listed as conservation status “Least Concern”, and are even less commonly available than denticulata, although in my opinion it forms a much more interesting growth pattern around the base of the plant. 

Care in Cultivation

They, like other cheiridopsis, need a fast-draining, gritty soil mix that is airy and allows for the roots to rapidly dry out. While they do best with regular winter water, it should be balanced with how cold the air temperatures are. I watered mine well when the temperatures were above 70 during the day, but let them stay dry if the weather cooled off. 

Compared to the other cheiridopsis in my collection, these seem easier, particularly to encourage them to bloom. Provide plenty of morning sunlight (or late afternoon), and keep them shaded for the hottest part of the day. 

cheiridopsis pillansii

Cheiridopsis pillansii

These have thick, almost finger-like leaf bodies that are soft, fleshy, and have a texture reminiscent of the sharp-tooth from the Land Before Time (not to be outdone by Pleiospilos nelii, though).

In the wild, these are listed as CITES 2, meaning that unless their trade is controlled (particularly for field collected specimens), they may become a threatened species. That being said, they’re not currently threatened – just that they might be. Any species that resemble them are also protected under this classification.

Another common name for this species is “Lobster Claws”, which is appropriate considering their fat little leaf bodies. If you look at the photo to the left, it’s not hard to imagine where the name came from. 

Care in Cultivation

The theme of winter growers that thrive in well-draining, gritty, sandy soil continues with these.

They do best with regular water in winter, and will go dormant in summer. Night time temperatures above 50 – 55F seem to trigger summer dormancy, although with ideal conditions and occasional water, they will continue to grow even in winter months.

Mine have yet to bloom, but they should produce large yellow flowers that are highly scented. Sometimes blooms can range from pink to orange in color; I am most looking forward to the scented part of the bloom, though! 

They are relatively easy to establish as imports or bare root specimens; the one to the left came in as a single head specimen with a miniscule root base from a European exporter. In less than a year, you can see that it has grown significantly, and is easily one of the favorite mesembs in my collection. 

Titanopsis

A small genus of only about 10 species, these are split between several areas of South Africa. This means that their watering needs vary greatly by species, with some needing winter water and others needing summer. 

Care of Titanopsis

These little mesembs need very well draining soil, with a high quantity of inorganic medium compared to organic. It is essential to know your species’ growing season, as water during the wrong time of year can rapidly cause rot and issues. 

titanopsis calcearum

Titanopsis calcareum

Beautiful little stone plants that have white, crusted-looking growths at the edge of their leaves to help them blend in to the limestone outcrops they are native to. With time and good care, they have a mat-like growth habit, developing rosettes up to 4″ wide. They produce showy flowers in late fall through winter, typically bright orange or yellow.

Care in Cultivation 

At a Glance: One of the most forgiving Titanopsis species; very cold hardy if kept dry in winter. 

Soil: Use a very well draining mix. Up to 75% inorganic medium recommended, with pumice and grit mixed with a small portion of organic matter such as peat moss, orchid bark, coconut coir, with the addition of a minute amount of worm castings if mixing from scratch. Simply adding a small amount of succulent soil is effective. 

Watering: I have had success with minimal watering in spring and fall, and I strive to keep them dry otherwise. I have one specimen in-ground on my “mesemb hill” and so far it has tolerated extreme heat, dryness, and regular water in summer as well as unusual winter rains this year (2021-2022 rainfall season). The in-ground plant is in nearly full inorganic ‘soil’, mostly quartz and granite stones, which likely has an impact. 

Cold hardiness: If dry, can tolerate temperatures well below freezing, even under a thin layer of snow. My personal plants have shrugged off nights in the low 30s, with the in-ground plant looking fine after a frosty night following heavy rain the day before. Appropriate drainage is key. 

Fertilizing: Little to none is needed. In high inorganic soil blends, a half strength fertilizer at the start of the winter growing season is likely appreciated. 

Sun exposure or lighting: Prefers very bright light, with nearly full sun being ideal. Readily stretches if not kept adequately bright. During the long hot days of summer, placements with shade during the hottest part of the day are recommended for best appearance. 

Propagation: Larger plants may be divided and propagated that way; also grows readily from seed. 

MORE COMING!