SUCCULENT SUNDAY: Euphorbia obesa v symmetrica—the UFO has landed

Chief among the pleasures of succulents are their otherworldly shapes and colors. Euphorbia obesa is a very familiar shape... familiar, that is, in a beach ball or balloon! This oblate spheroid is not a common shape in the world of plants.

This UFO-shaped plant is dioecious (unisexual). I think the plant pictured is male, but I'm not completely sure. On my to-learn list is better positive identification of the sex of euphorbia blooms (called cyathia).

Euphorbia obesa var symmetrica

With any luck, I'll have a breeding pair of these choice succulents from southern Africa. Here's my second plant. Look at the cute second body! This kind of branching is quite unusual in this species:

Euphorbia obesa grows wild in the Graaff-Reinet district in the Eastern Cape. The form pictured here (subspecies symmetrica) is found in the Willowmore district, where it's protected voluntarily by some farmers, partly with the effort of enthusiasts from the Euphorbia Study Group of Warrington, England.

The subspecies symmetrica is distinguished from the base type by a rather technical distinction: it produces multiple peduncles from single flowering eyes. Amateur growers and fans of this plant also know that Euphorbia symmetrica stays compact, rather than elongating and growing tall like the species type, Euphorbia obesa.
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See Also
Euphorbia obesa ssp symmetrica at Cactus-Art.Biz

SUCCULENT SUNDAY: Kalanchoe eriophylla, thou woolliest of leaves

Also posted at SentientMeat.Net

I confess a personal weakness. I cannot resist the wildlife of Madagascar. Lemurs, aloes, bryophyllums, kalanchoes... This may be exoticism, orientalism, or some other unhealthy fascination. Probably the only cure—as with the phobias—is to confront the object of my obsession and see Madagascar in person. Soon, baby, soon.

Kalanchoe eriophylla grown & photographed by Mr Sentient Meat

The genus Kalanchoe is found in almost all of Madagascar's many regions and climates, except the central plains. Kalanchoe comprises about 100 species, of which 60 are endemic to Madagascar.
Many species of Kalanchoe have adapted a woolly or fuzzy tomentum: fibrous, protective leaf covering. Of these, Kalanchoe eriophylla (from Greek words for woolly and leaves) may be the woolliest of all. Its covering is even denser than that of the more common "Panda Plant" Kalanchoe tomentosa.

E.J. Lucas reports this wool is Kalanchoe eriophylla's adaptation to high montane Madagascar—moderate temperatures but punishing ultraviolet. Whatever the cause, Kalanchoe eriophylla is highly attractive and extremely pettable. In person, it's almost irresistible. What's more, it is adapted to a scrambling existence on mountainsides, so its stems can re-root along their length. This makes it fairly easy to propagate, though too much water or heat can kill it quickly.

Kalanchoe eriophylla pale-pink flower borne on long stalks with fuzzy sepals, photo by Pilar at Infojardin

Kalanchoe eriophylla was originally described (the word botanists prefer over discovered) in 1857 from a plant collected by Bojer on Mt Antogona, Imerina province. Reference specimens have been collected for herbariums from the central Madagascar Ankaratra massif, and the areas surrounding Tananarive, Imerina province. As recently as 1995, the species was reported "very abundant". Pieces are sold in markets and worn by Malagasy people as a good-luck charm, particularly in business or acquiring riches.

One of several common Malagasy names for Kalanchoe eriophylla is "Felatanantsifoana", meaning "palm of the hand never empty".

Kalanchoe eriophylla flower closeup, photo Creative Commons copyright 2009 Zoya Akulova

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See Also

Lucas, E. J. (2002), Plate 452. Kalanchoe Eriophylla Crassulaceae. Curtis's Botanical Magazine, 19: 232–236. doi: 10.1111/1467-8748.00354
Kalanchoe eriophylla at Encyclopedia of Life

SUCCULENT SUNDAY: Aloe haworthioides, fuzzy wisps with fragrant flowers

Also posted at SentientMeat.Net

Aloe haworthioides (Baker, Central Madagascar) has been blooming for over a week. It's diminutive at just 3 inches across.

Aloe haworthioides Baker, 3" pot, in full fragrant bloom. Flowers smell sweet, almost like orange blossoms.

Flowers are a big draw in the yard even if you're like me, more of a foliage lover. Flowers are a sign the plant is doing well, of its fitness for... well... sex. Today was New Year's Day and the weather was 80 degrees F and sunny, so the winter flowers were heavy with scent.

Aloe haworthioides startled me with the delicious sweetness of its fragrance. You have to sniff very close, but then it smells gorgeous.

Aloe haworthioides flower closeup

The genus Aloe practically defines the pursuit of defining genus of cactus and succulent culture. You can grow giant tree aloes up to 15 meters in height—Aloe barberae, Aloe pillansii, Aloe dichotoma, just to name 3. I have humble specimens of all three, and I love them.
To Aloe barberae's dragon, Aloe haworthioides is a dragonfly .

Aloe haworthioides, closeup of 3" body

Aloe haworthioides is named for the resemblance to its cousins in genus Haworthia. This resemblance is not coincidence; Aloe and Haworthia are genetically close and they hybridize easily.
Speaking of hybridizing, Aloe haworthioides is often used in aloe breeding. Its beauty and promiscuity are also drawbacks: many plants billed and sold as Aloe haworthioides are actually careless crosses from uncontrolled pollination. Sounds sexy... but be careful out there!

In the wild, it makes its home in the central mountains of Madagascar at an altitude of 1200-1800 m above sea level. Although a slow grower, it forms offsets and can reportedly be propagated by cuttings, i.e. removing these offsets.

Aloe haworthioides is stemless, perennial and herbaceous.

Here are some more technical details, cribbed from Peter Lapshin's site. (Someone—Saturn, Santa, or Satan—needs to bring me the new comprehensive book on the genus, Aloes: The Definitive Guide.)

Each plant body has up to 100 leaves, 3–4 cm long, approximately 6 mm wide, gray-green with white buds, arranged  in a dense rosette diameter of 4-5 cm, leaf margins with harmless white hairs or spines. Flower stems 20-30 cm tall, flowers fragrant, white or pale pink, 6-8 mm in length.

Aloe haworthioides from Peter Lapshin's site, http://www.lapshin.org/succulent/o-al-haw.htm

See Also

Aloe haworthioides at Peter Lapshin's site
Aloe haworthioides at Dave's Garden PlantFiles

SUCCULENT SUNDAY: Haworthia tessellata, waxy windowed whorls

Haworthia tessellata 'Neat' shooting a bloom stalk. Can you see the windows in the leaf tops?

Haworthia tessellata is one of my favorite plants. At least, that's what I tell people. At least one friend has complained that I say that about so many plants that it can't possibly be true.

Haworthia limifolia, a close relative of H tessellata but lacking obvious windows in its leaves. It resembles opaque, molded plastic rather than translucent, carved wax.

The latin name tessellata comes from the tiled pattern in the leaf faces. Attractive, yes, but the bigger truth about these odd, waxy leaf faces is this: they evolved to be natural windows. Many Haworthia have adapted this way. Sunlight enters the plant body through these translucent windows and is converted into energy by many layers of chlorophyll-rich cells. This is especially useful in the arid climates where Haworthia tessellatamakes its living; the primary photosynthesis tissues are not exposed to the drying elements.

Haworthia tessellata 'Fang', a select clone named for the teeth and tubercles on the leaf undersides.

Leaves with window tops are described as fenestrate, from the Latin for window: fenestra.

Haworthia tessellata 'Super Tessellata', a beautiful, select clone

What's more, like many succulents, Haworthia tessellata can photosynthesize using Crassulacean Acid Metabolism (CAM). During CAM photosynthesis, the plant opens its stomata only during the cool of the night. It "inhales" in carbon dioxide and stores it in its thick, succulent tissues (while "exhaling" oxygen). During the heat of the day, the carbon dioxide stored deep in the plant can be used in photosynthesis because sunlight passes through the leaf windows, deep into the center of each leaf.

Haworthia tessellata in habitat. Photo by Jakub at http://haworthia-gasteria.blogspot.com/

See Also
Convergent Evolution in Succulent Desert Plants: Comparing Haworthia and Aloe (Africa) With Agave (America)

SUCCULENT SUNDAY: Adenia stylosa, purple vine of evil

Also posted at SentientMeat.net

Adenia stylosa, photo by Mr Sentient Meat of his plant

Okay, maybe Adenia stylosa isn't truly evil. But its heart-shaped purplish leaves are the color of a deep wound. They do have dark red veins. And consider the stem... the gnarled, waxy, green, enlarged trunk or caudex. To me it looks like a living version of a melted candle destined for a Satanic ritual. In fact this plant's common name is reportedly "Candlestick Plant". That's fitting, as far as it goes. It does lack a bit of punch, a bit of drama. I think we should all start calling it "Satan's Candle". Who will be the wiser? Common names don't really matter anyway. Whatever you call it, it's a plant straight out of Charles Addams or Edward Gorey.

Adenia firingalavensis v. stylosa "Candlestick Plant"

Now to the anatomy of evil... or at least the secrets behind Adenia stylosa's macabre appearance. Its above-ground tuber... okay, "tuber" doesn't sound very evil... this caudex even has vaguely anatomical "hips": actually a distinctly swollen hypocotyl, the portion of the stem below where its cotyledons were attached and fell away in the seedling's infancy. The leaves are dark and attractive, varying between individuals as shown in this picture by Olaf Pronk.

Leaves from different individuals, all Adenia stylosa

Adenia stylosa was known previously as a subspecies of Adenia firingalavensis or Adenia epigea but is now considered a separate species. It lives in Northern Madagascar, in Ankarana National Park among other places.

Famed tsingy, limestone formations in Ankarana, Madagascar

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See also:
Rauh, Werner. Succulent and Xerophytic Plants of Madagascar. Strawberry Press.

1995. Volume 1. ISBN 10: 0912647140. ISBN 13: 9780912647142

1998. Volume 2. ISBN 10: 0912647175. ISBN 13: 9780912647173

David J. Hearn has found strong enough DNA evidence and differences in its form to separate Adenia stylosa as a distinct species, moving it from its historical classification as variations or subspecies of Adenia firingalavensis or Adenia epigea. From the scientists' abstract:

[T]he position of A. stylosa has been clarified. This species was once treated as A. firingalavensis var. stylosa, and prior to that as A. epigea var. stylosa, but molecular and morphological data suggest it is separate from these species.

Hearn, D. J. 2007. Novelties in Adenia (Passifloraceae): Four new species, a new combination, a vegetative key, and diagnostic characters for known Madagascan species. Brittonia 59(4): 308–327.

Huntington Botanical Garden's introduction of related Adenia epigea

SUCCULENT SUNDAY: Dorstenia lavrani, one sex at a time

Also posted at SentientMeat.net

Dorstenia lavrani, too young to be sexually active
(no hypanthodia),  photo by Sentient Meat

After you read about the bizarre sex life of figs and fig wasps, you can't really say that the genus Dorstenia is much stranger than other members of the fig family, Moraceae. Still, you can't help but notice the bizarre blooms of Dorstenia called hypanthodia. They look like psychedelic set decorations from the original Star Trek.

Photo of Dorstenia hybrid hypanthodium by Josiah Hartzell
Ripe seeds are ejected and may land far from the mother plant

Dorstenia has about 100 species. Most are monoecious with bisexual hypanthodia, but today's focus, Dorstenia lavrani, is dioecious, meaning some plants are male and bear pollen, while others are female and bear ovaries and later, seeds. My young plant has not borne any hypanthodia yet, so I don't know its sex. I hope it's female.

Same Dorstenia lavrani pictured above

Legendary plant explorer John Lavranos discovered this plant variety in 1973, but it was circulated among collectors as a form of Dorstenia foetida -- a fascinating but much more common plant -- identified only by its locality, Taba'a Gap or Taba'a Gorge. It was finally described as a distinct species and named Dorstenia lavrani only in 2008.

Beautiful, prizewinning plant about 14 inches high
(not counting the Sideshow Bob topknot)
grown by Yvonne Hemenway, iPhone snapshot by Sentient Meat

Dorstenia lavrani mesmerizes me with its pale, wax-like skin and its helix of leaf scars running up and down each stem. Well grown plants are visually striking, magnetic to growers and plant show judges alike. Apparently animals also find it irresistible -- it was the first plant to be devoured off my deck. (The small plant pictured here is its replacement.) The first day I noticed a problem, only a nibble was missing. The next day all that remained of that plant was a crater in the soil.

Breeding female Dorstenia lavrani at Mike and Maureen Massara's growing grounds
photo by Bruce Brethauer, Columbus Cactus Club

SUCCULENT SUNDAY: Avonia buderiana: tiny stems covered with papery white scales, tipped with fragrant white flowers

Also posted at Sentient Meat blog

Avonia recurvata ssp buderiana, new addition to Sentient Meat container garden
grown and sold by Woody Minnich of Cactus Data Plants

Which plants bewitch you? Which traits arouse the most passion? Even if pressed, I can't narrow my favorite plants down to just 10 or even 100, but I can tell you which traits amaze me. I am endlessly fascinated by plants which don't look like plants... or in some cases, don't resemble living things from the planet Earth.

Avonia buderiana is just such a plant. Its tiny branches reach upwards in haphazard, coral shapes (coralliform) covered with bizarre, overlapping, white, papery scales. These scales are actually modified leaf parts (stipules) which protect the tender branches and minute green leaves from heat, sun, and dehydration. Some Avonia live in quartz sands where their papery white scales blend visually with their habitat. All Avonia are dwarfs; A buderiana stems reach at most 80mm or scarcely over 3 inches in height.

The ephemeral white flowers sprout from the tips of the stems, usually 1 per stem. They open briefly in the heat of the day but are usually closed like tiny, out-worldly pincers.

Avonia buderiana grows wild in Helskloof, Richtersveld, in the Northern Cape of South Africa.

Dirt road and horizon, showing arid habitat
Helskloof, Richtersveld, Northern Cape, South Africa
photo by Sakkie on Panoramio

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Richtersveld Transfrontier National Park, South Africa official site

Court, Doreen. (Third Edition, 2010). Succulent Flora of Southern Africa. Cape Town, South Africa: Struik Publishers. ISBN-10: 1770075879. ISBN-13: 978-1770075870.

Photo from Spain plant vendor Cactus Serrano www.cactuserrano.es

View from Maerpoort with Rosyntjieberg in the background, Richtersveld National Park
Photo by Lex Hes, courtesy of, and copyright, South Africa Tourism, a department of the government of South Africa.

SUCCULENT SUNDAY: Echinopsis schieliana, upturned birds' nests waving fancy red frocks

When I bought this Lobivia schieliana (syn Echinopsis schieliana), it had no flowers or buds. I got it for the wonderful spines, which turn the rounded (globose) stems of the plant into little inverted birds' nests. It was a homely beauty, a miniature sculpture of meticulously attached pieces of straw spun into whorls. It was in fact a perfect example of a particular cactus aesthetic: curious, ugly-as-beautiful — the implicit danger of spines, tamed by culture... and in this case, by the plant's tendency to use its defensive spines as horny shield rather than stabbing weapons.

And then... out of nowhere... the blooms. Shocking red, raised above the body of the plant on narrow tubes — the better to be seen by their dancing partners... hummingbirds? Much as I want to write about my other strange cacti — exquisite snowy globes or pineapples with spines like bouquets of grass — I can't ignore these flowers any better than the hummingbirds can.

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PS One of the... I say THE... references on cactus just arrived in the mail and I'm very excited: The Cactus Family (2001) by Edward F. Anderson. He writes,

Echinopsis schieliana (Backeburg) D. R. Hunt 1987

Lobivia schieliana Backeberg 1957, L. backeburgii subsp. schieliana (Backeburg) G. D. Rowley 1982Lobivia quiabayensis Rausch 1968, Echinopsis maximiliana subsp. quiabayensis (Rausch) G. D. Rowley 1982Lobivia leptacantha Rausch 1972

Plants often forming clusters from basal branching. Stems globose to cylindrical, often slender, to 4.5 cm (1.8 in) long and 3.5 cm (1.4 in) in diameter. Ribs about 14. Central spine one, often absent at first, bent downward, light brown, 5–6 mm (0.2 in) long. Radial spines about 14, pectinate to radiating, interlacing, light brown. Flowers bright light red; floral tubes slender. Distribution: Peru and Bolivia.

Lithops spp: stolid prima donnas, down-to-earth yet delicate

Lithops sp, tentatively L marmorata, on 2nd day of bloom.
The largest body here is under 2 inches at its widest.

When you walk down the aisle of a plant show or even a nursery department in a big-box store, certain succulents reach out and knock you over. They barely look like plants. In fact, sometimes it's hard to believe they're even alive. Lithops are tiny but they fall into this drop-dead category.

With a name from the Greek for stone and eye or face, Lithops or "Living Stones" are small plants native to the dry Western Cape region of Southern Africa. They are in the same family (Aizoiaceae) as ice plants, also originally from Southern Africa and spread the world over by human travel and other transport.

Unlike their ice plant cousins, cultivated for centuries and easy to care for, Lithops are widely known only since the 1950s (with the collecting and cataloging work of Desmond and Naureen Cole). Not only did they emerge from obscurity recently — they also have a reputation for being somewhat difficult for amateur cacti and succulents growers. (I have killed quite a few of them, and the Lithops flowers pictured are some of my first.) Lithops are adapted to a dry existence, and if watered too much or at the wrong time they can succumb quickly to that omnipresent nemesis of succulent fanciers: rot.

Lithops care is less of a puzzle once you learn a basic lesson about about their special needs in winter: briefly, don't feed or water them. They are not truly dormant, but they are busy with a small, vital, inner task: growing a new leaf pair in the center of the plant. As the new pair (or pairs) grow, they absorb the nutrients from the previous year's pair. The outer pair shrivels and the inner pair (or pairs) emerges from the seam between the two dying leaves. If you water them during this period, you risk rotting the plant or preventing the outer leaves from being absorbed. Even if the plant survives, this can lead to a misshapen and unnatural look, living blobs instead of neat roundish tiles.

Mid-October, the time of this post, is prime time for Lithops flowers. They like to make hay while the sun still shines.

References

Lithops gallery

Lithops.info 

Cole, Desmond; Cole, Naureen (2005). Lithops—Flowering Stones. Cactus & Co. 368 pages (20.7 × 29.5 cm), 644 col. + 5 b/w photos, 3 col. + 85 b/w drawings, 7 maps, 98 habitat photos. ISBN-10 88-900511-7-5. ISBN-13 978-88-900511-7-3

Hammer, Steven (2010). Lithops: Treasures of the Veld. 2nd Edition. BCCS. Softbound; 156 pages; 238 photos. ISBN-10: 0902099922. ISBN-13: 978-0902099920.

Shimada, Yasuhiko (2001). The Genus Lithops. Dobun Shoin. 240 pages (19 × 26.5 cm), 437 col. photos, 1 b/w map. ISBN-10 4-8103-4066-X.

Hoodia pilifera: like a liliputian cactus, but from Africa

You can't wade very far into the study of evolution, plant taxonomy -- or the pursuit of growing exotic succulents at home -- without smacking right into convergent evolution. That's the notion that certain distantly related plants have evolved features which make them seem much more alike than their DNA (or evolutionary pedigree) would predict.

Hoodia pilifera, 3.5" tall, like a tiny saguaro
South Africa (Western Cape, Little and Great Karoo)
photo by Sentient Meat

As I've learned more about it, I've come to the conclusion that there are two kinds of convergent evolution: the superficial, obvious kind and the subtle, fool-a-scientist kind. The more subtle kind of convergent evolution -- the kind that can fool a scientist -- shows up in the study of plant taxonomy (the classification of plants into species, genus, and family based on how closely they're related). Just as DNA science has revolutionized how crimes are solved (and revealed that some imprisoned felons are actually innocent), the study of DNA in plants has revealed that plants once believed by scientists to be closely related (due to similarities in stem, leaves, flowers, or seeds) are actually quite distant relatives. They developed their similarities independently -- and well after their ancestors had split off from each other. As a result, the family tree (for example, of Euphorbia¹) has been in a state of ongoing upheaval as the contemporary field of molecular phylogenetics revises our knowledge of evolutionary relationships and reveals many cases of subtle, scientist-fooling, convergent evolution.

Actual saguaro, approx 100x taller than our H pilifera
photo by Leonard G. / Wikipedia - Creative Commons ShareAlike 1.0 license

In grade school we learn the more obvious kind of convergent evolution -- a sort of gee-whiz, ain't-Nature-grand, intercontinental shape-matching game, in which we are amazed that plants from Africa (like spiny euphorbs and today's feature, Hoodia pilifera) bear such a striking, if superficial, resemblance to desert cactus (like the majestic saguaro, pictured), which hail exclusively from the Americas.
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¹Credit goes to Brian Dorsey from University of Michigan for turning me on to the turmoil and excitement in genus Euphorbia (or wails of anguish, depending how attached you are to old classifications) in his talk, "Systematics of the xerophytic and succulent Euphorbia" at 28th Succulent Plants Symposium. Much of this turmoil comes from correcting errors in classification (and our accompanying model of the evolutionary family tree) which can be blamed on subtle cases of convergent evolution within Euphorbia.

Coryphantha elephantidens in magenta-and-pink glory

This 3-inch, pink and magenta bloom surprised your guest contributor (Sentient Meat) this week, a shining beacon from the patio rooftop where it was living with a few other sun-soaked and rather neglected cacti and succulents. (Los Angeles has been hot for a couple weeks and the plants on this roof are all looking a bit worse from the relentless exposure.)

The bud had gone overlooked, but it was impossible to overlook this flower. This is the first time I've seen this cactus in bloom. It was purchased without a label, but I believe it's Coryphantha elephantidens. I love the color gradient from light pink at the edge the petals to deep magenta at the center tips.

After such an attention-grabbing display, the plant was moved to a more sheltered existence on the deck. Sometimes it pays to show off.

Coryphantha elephantidens showing deep pink flower and beginning to branch and clump